The American Journal of Sports Medicine

Short-term and mid-term differences between hamstring and patellar tendon autografts for anterior cruciate ligament (ACL) reconstruction are well documented. Systematic reviews highlight the lack of long-term results between the two grafts.

Seventeen years after ACL reconstruction, no difference will be found in functional outcome, quality of life, and graft failure between patients with patellar tendon (PT) or semitendinosus and gracilis tendon (STG) autografts; however, a significant difference will be seen in the prevalence of osteoarthritis.

Randomized controlled trial; Level of evidence, 2.

Sixty-four patients were included in this prospective study (32 in each group). A single surgeon performed primary ACL reconstruction in alternating sequence. Forty-eight patients (24 in each group) were evaluated 17 years after ACL reconstruction: A clinical assessment was made based on the International Knee Documentation Committee (IKDC) form, instrumented laxity was measured with KT-1000 arthrometer, and radiography of the operated knee was conducted and assessed for degenerative disease. The Lysholm questionnaire and the Short Form–36 version 2 questionnaire were filled out by the patients.

At the 17-year follow-up, no statistically significant differences were seen with respect to graft failure (2 reruptures in the semitendinosus and gracilis tendon [STG] group [6.3%] and 3 reruptures in the PT group [9.4%]) and functional outcome. Increased instrumented laxity (>3 mm) measured with KT-1000 arthrometer was seen in significantly more patients in the STG group (8 in the STG group compared with 2 in the PT group; P = .03) with a mean side-to-side difference of 2.17 ± 1.86 mm in the STG group compared with 1.33 ± 1.93 mm in the PT group. A significant difference was found in frequency of knee osteoarthritis (OA)—100% in the PT group compared with 71% in the STG group (P = .004). Patients in the PT group tended to have higher grade OA according to the IKDC grading system, with an average grade of 1.46 in the PT group compared with 1 in the STG group (P = .055). The degenerative changes in the PT group were more common in the medial and patellofemoral compartments (P = .003 and P = .04, respectively).

Both autografts provided good to excellent subjective outcomes. No significant differences were noted in graft failure and clinical instability. However, significantly more patients in the STG group had increased instrumented anteroposterior translation measured with KT-1000 arthrometer, and there was a greater prevalence of knee OA at 17 years after surgery in the PT group.

Historically, outcomes of posterior cruciate ligament (PCL) reconstructions have been less predictable and reported to yield inferior results when compared with those for anterior cruciate ligament (ACL) reconstructions.

To report on the outcomes of double-bundle PCL reconstructions (DB PCLRs) in isolated versus combined injuries and acute versus chronic PCL reconstructions. To compare the outcomes of isolated DB PCLR with isolated ACL reconstruction.

Cohort study; Level of evidence, 3.

All patients who underwent a primary endoscopic DB PCLR for complete PCL tears (grade III) between May 2010 and March 2015 were reviewed. Patient-reported outcome scores (Tegner, Lysholm, WOMAC [Western Ontario and McMaster Universities Osteoarthritis Index], SF-12 [12-item Short Form Health Survey]) and objective posterior stress radiographs were collected preoperatively and at a minimum 2 years postoperatively. A cohort subanalysis was additionally performed between isolated and combined PCL reconstruction and acute versus chronic PCL reconstruction. Patients who underwent isolated ACL reconstructions over the same inclusion period (2010-2015) were selected as a comparison group.

One hundred patients who underwent DB PCLR were included in this study. There were 31 isolated PCL injuries, and 69 patients had concurrent combined PCL injuries requiring surgery. The mean follow-up for the PCL cohort was 2.9 years (range, 2-6 years). The median Tegner activity score improved from 2 to 5, Lysholm from 48 to 86, WOMAC from 35.5 to 5, and SF-12 Physical Component Summary from 34 to 54.8 (all P values <.001). The mean side-to-side difference in posterior tibial translation on kneeling stress radiographs improved from 11.0 ± 3.5 mm preoperatively to 1.6 ± 2.0 mm postoperatively (P < .001). There were no differences in postoperative functional scores between isolated PCL reconstructions and PCL-based multiligament reconstructions (all P values >.229). There was no significant difference in the reported outcome scores between acute and chronic reconstructions (all P values >.087) except for Tegner scores (P < .001) and patient satisfaction (P = .011) favoring acutely treated PCL injuries. There were no significant differences between patients who had an isolated DB PCLR and patients who underwent an isolated ACL reconstruction (n = 141) in postoperative outcome scores (all P values >.064).

Significantly improved functional and objective outcomes were observed after anatomic DB PCLR at a mean 3 years’ follow-up, with low complication rates, regardless of concomitant ligamentous injury or timing to surgery. Additionally, contrary to previous reports, comparable subjective and functional clinical outcomes were achieved compared with an isolated ACL reconstruction control cohort.

The prevalence of osteoarthritis after successful meniscal repair is significantly less than that after failed meniscal repair.

To determine whether the addition of anterolateral ligament reconstruction (ALLR) confers a protective effect on medial meniscal repair performed at the time of anterior cruciate ligament reconstruction (ACLR).

Cohort study; Level of evidence, 3.

Retrospective analysis of prospectively collected data was performed to include all patients who had undergone primary ACLR with concomitant posterior horn medial meniscal repair through a posteromedial portal between January 2013 and August 2015. ACLR autograft choice was bone–patellar tendon–bone, hamstring tendons (or quadrupled hamstring tendons), or quadrupled semitendinosus tendon graft with or without ALLR. At the end of the study period, all patients were contacted to determine if they had undergone reoperation. A Kaplan-Meier survival curve was plotted, and a Cox proportional hazards regression model was used to perform multivariate analysis.

A total of 383 patients (mean ± SD age, 27.4 ± 9.2 years) were included with a mean follow-up of 37.4 months (range, 24-54.9 months): 194 patients underwent an isolated ACLR, and 189 underwent a combined ACLR + ALLR. At final follow-up, there was no significant difference between groups in postoperative side-to-side laxity (isolated ACLR group, 0.9 ± 0.9 mm [min to max, –1 to 3]; ACLR + ALLR group, 0.8 ± 1.0 mm [min to max, –2 to 3]; P = .2120) or Lysholm score (isolated ACLR group, 93.0 [95% CI, 91.3-94.7]; ACLR + ALLR group, 93.7 [95% CI, 92.3-95.1]; P = .556). Forty-three patients (11.2%) underwent reoperation for failure of the medial meniscal repair or a new tear. The survival rates of meniscal repair at 36 months were 91.2% (95% CI, 85.4%-94.8) in the ACLR + ALLR group and 83.8% (95% CI, 77.1%-88.7%; P = .033) in the ACLR group. The probability of failure of medial meniscal repair was >2 times lower in patients with ACLR + ALLR as compared with patients with isolated ACLR (hazard ratio, 0.443; 95% CI, 0.218-0.866). No other prognosticators of meniscal repair failure were identified.

Combined ACLR and ALLR is associated with a significantly lower rate of failure of medial meniscal repairs when compared with those performed at the time of isolated ACLR.

Donor site morbidity in the form of anterior knee pain is a frequent complication after bone–patellar tendon–bone (BPTB) autograft anterior cruciate ligament (ACL) reconstruction.

The purpose was to examine the effect of the intraoperative administration of platelet-rich plasma (PRP) on postoperative kneeling pain. It was hypothesized that PRP treatment would reduce knee pain.

Randomized controlled trial; Level of evidence, 2.

Fifty patients (mean ± SD age, 30 ± 12 years) undergoing BPTB ACL autograft reconstruction were randomized to the PRP (n = 27) or sham (n = 23) treatment. In either case, 10 mL of venous blood was drawn before the induction of anesthesia and either discarded (sham) or processed (PRP) for preparation of a PRP gel to be later mixed with donor site bone chips and inserted into the patellar defect. At 12 weeks, 6 months, 1 year, and 2 years after surgery, patients completed International Knee Documentation Committee (IKDC) forms and visual analog scale pain scores for activities of daily living and kneeling. Healing indices at the donor site were assessed by routine noncontrast magnetic resonance imaging (MRI) at 6 months. Mixed-model analysis of variance was used to assess the effect of PRP on patient symptoms and MRI indices of donor site healing, as measured by the width of the donor site defect.

Kneeling pain, pain with activities of daily living, and IKDC scores were not different between treatment groups at any of the time intervals (P = .08-.83). Kneeling pain improved from 12 weeks to 6 months and from 1 to 2 years (P < .05). IKDC scores improved substantially from 12 weeks to 6 months (P < .001) and continued to improve to 2 years (PRP, 86 ± 19; sham, 89 ± 10). MRI indices of donor site healing were not different between treatment groups (P = .53-.90).

Whether randomized to receive PRP in their patellar defect or not, patients continued to have similar levels of kneeling pain and patellar defect sizes after autograft BPTB ACL reconstruction.

NCT01765712 (ClinicalTrials.gov identifier).

Few studies have evaluated the influence of anterior cruciate ligament (ACL) reconstruction on the outcome of cartilage repair.

The purpose was to investigate the association between ACL reconstruction and functional outcomes after osteochondral allograft (OCA) transplantation. The hypothesis was that patients treated with OCA transplantation who had a history of ACL reconstruction would have inferior clinical outcomes and lower osteochondral graft survivorship when compared with a matched group of patients undergoing OCA transplantation without a history of ACL reconstruction.

Cohort study; Level of evidence, 3.

This study compared 31 knees that underwent OCA transplantation with a history of ACL reconstruction (OCA and ACL group) and 62 knees treated with isolated OCA transplantation (OCA group) that had an intact ACL. Groups were matched by age, diagnosis, year of surgery, and graft size. Minimum follow-up was 2 years. Frequency and type of reoperation were assessed. Clinical failure was defined as revision OCA transplantation or conversion to arthroplasty. Subjective outcome measures included International Knee Documentation Committee scores, Knee injury and Osteoarthritis Outcome Scores, and patient satisfaction.

Clinical failure occurred in 3 of 31 knees (9.7%) in the OCA and ACL group and 6 of 62 knees (9.7%) in the OCA group (P ≤ .999). Five- and 10-year survivorship of the OCA was 94.7% and 82.3% for the OCA and ACL group and 93.4% and 79.6% for OCA group, respectively (P = .979). Mean follow-up was 6.2 ± 3.3 years among all knees with grafts in situ. Changes from preoperative to latest follow-up visit (difference scores) on all subjective outcome measures were greater in the OCA group; however, none of the difference scores were statistically significant. Satisfaction with the results of OCA transplantation was reported in 78.3% of the OCA and ACL group and 71.7% of the OCA group (P = .551).

Treatment of cartilage lesions with OCA transplantation proved to be reliable and effective regardless of a history of ACL reconstruction as demonstrated by the improvements in outcome scores, long survivorship, and high satisfaction rates. History of ACL reconstruction did not influence outcome of OCA transplantation.

Meniscus injuries and associated meniscectomies cause patients long-term pain and discomfort and can lead to joint deterioration.

To evaluate a collagen-hyaluronan sponge reinforced with synthetic resorbable polymer fiber for total meniscus reconstruction in a long-term ovine model.

Controlled laboratory study.

Eleven skeletally mature sheep were implanted with the total meniscus scaffold. At 2 years, explants were evaluated biologically (radial/circumferential histology, immunofluorescence) and mechanically (compression, tension), and articular surfaces were examined for damage.

The fiber-reinforced scaffold induced formation of functional neomeniscus tissue that was intact in 8 of 11 animals. The implant was remodeled into organized circumferentially aligned collagen bundles to resist meniscus hoop stresses. Moreover, type II collagen and proteoglycan deposition near the inner margin suggested a direct response to compressive stresses and confirmed fibrocartilage formation. Cartilage damage was observed, but end-stage (severe) joint deterioration associated with meniscectomy was avoided, even with limitations regarding the ovine surgical procedure and postoperative care.

A fiber-reinforced total meniscus replacement device induces formation of functional neomeniscus tissue that has the potential to prevent catastrophic joint deterioration associated with meniscectomy.

An off-the-shelf meniscus device that can be remodeled into functional tissue and thus prevent or delay the onset of osteoarthritis could address a widespread clinical need after meniscus injury.

Adjustable-loop cortical buttons for femoral fixation of bone-tendon-bone grafts have potential advantages over interference screw fixation; however, these devices have not been benchmarked biomechanically against interference screws.

The purpose was to compare the time zero biomechanical properties of commercially available, adjustable-loop cortical button and metallic interference screws for femoral fixation of bone-tendon-bone grafts. It was hypothesized that no significant differences would be found in biomechanical properties between fixation techniques.

Controlled laboratory study.

Adjustable-loop cortical buttons (n = 8) and metallic interference screws (n = 8) were used to fix matched pairs of human bone-tendon-bone allografts in porcine distal femurs. These constructs were preconditioned (10 N to 50 N at 1 Hz, 10 cycles), subjected to cyclic loading (50 N to 250 N at 1 Hz, 500 cycles), and then pulled to failure at 20 mm/min.

The loads to failure (mean ± SD, 700 ± 256 N vs 688 ± 215 N, P = .92) and linear stiffnesses (219 ± 48 N/mm vs 218 ± 49 N/mm, P = .97) for the adjustable-loop cortical button and metallic interference screws, respectively, were not significantly different. Cyclic displacement was higher in the adjustable-loop cortical button group (2.1 ± 0.6 mm vs 1.3 ± 0.4 mm, P = .01). The mechanism of failure was different between groups, with bone block slippage occurring most commonly in the interference screw group (n = 5) and fracture of the bone block through the suture hole occurring most commonly in the adjustable-loop cortical button group (n = 6).

Adjustable-loop cortical buttons and interference screws have similar time zero failure loads, although cyclic displacement was higher with the adjustable-loop cortical buttons. The mean difference in displacement was less than 1 mm compared with the interference screw.

Adjustable-loop cortical buttons may be an acceptable alternative to an interference screw for femoral fixation of bone-tendon-bone grafts in anterior cruciate ligament reconstruction. The clinical relevance of the observed differences in cyclic displacement is unknown and should be evaluated in future studies.

During multiple knee ligament reconstructions, the graft tensioning order may influence the final tibiofemoral orientation and corresponding knee kinematics. Nonanatomic tibiofemoral orientation may result in residual knee instability, altered joint loading, and an increased propensity for graft failure.

To biomechanically evaluate the effect of different graft tensioning sequences on knee tibiofemoral orientation after multiple knee ligament reconstructions in a bicruciate ligament (anterior cruciate ligament [ACL] and posterior cruciate ligament [PCL]) with a posterolateral corner (PLC)–injured knee.

Controlled laboratory study.

Ten nonpaired, fresh-frozen human cadaveric knees were utilized for this study. After reconstruction of both cruciate ligaments and the PLC and proximal graft fixation, each knee was randomly assigned to each of 4 graft tensioning order groups: (1) PCL → ACL → PLC, (2) PCL → PLC → ACL, (3) PLC → ACL → PCL, and (4) ACL → PCL → PLC. Tibiofemoral orientation after graft tensioning was measured and compared with the intact state.

Tensioning the ACL first (tensioning order 4) resulted in posterior displacement of the tibia at 0° by 1.7 ± 1.3 mm compared with the intact state (P = .002). All tensioning orders resulted in significantly increased tibial anterior translation compared with the intact state at higher flexion angles ranging from 2.7 mm to 3.2 mm at 60° and from 3.1 mm to 3.4 mm at 90° for tensioning orders 1 and 2, respectively (all P < .001). There was no significant difference in tibiofemoral orientation in the sagittal plane between the tensioning orders at higher flexion angles. All tensioning orders resulted in increased tibial internal rotation (all P < .001). Tensioning and fixing the PLC first (tensioning order 3) resulted in the most increases in internal rotation of the tibia: 2.4° ± 1.9°, 2.7° ± 1.8°, and 2.0° ± 2.0° at 0°, 30°, and 60°, respectively.

None of the tensioning orders restored intact knee tibiofemoral orientation. Tensioning the PLC first should be avoided in bicruciate knee ligament reconstruction with concurrent PLC reconstruction because it significantly increased tibial internal rotation. We recommend that the PCL be tensioned first, followed by the ACL, to avoid posterior translation of the tibia in extension where the knee is primarily loaded during most activities. The PLC should be tensioned last.

This study will help guide surgeons in decision making for the graft tensioning order during multiple knee ligament reconstructions.

Allograft tendon used in anterior cruciate ligament reconstruction (ACLR) requires sterilization before implantation. Low-dose gamma irradiation is a means of sterilization that may minimize tissue damage.

To quantify the variability in mechanical properties between low-dose irradiated Achilles tendon allografts used for ACLR.

Descriptive laboratory study.

A total of 15 intact outer-third Achilles tendon allograft specimens were collected from the remains of full Achilles allografts used for intraoperative ACLR at a single hospital. All grafts were obtained from a single tissue bank and underwent proprietary disinfection and low-dose gamma irradiation (1.5-2.5 Mrad). Biomechanical testing was carried out to measure tendon elongation, failure location during tensile testing, maximum stress, maximum strain, and modulus of elasticity. The mean and standard deviation were calculated for each outcome measure, and the variability between specimens was calculated by the coefficient of variation (CV). The effect of donor age on graft material properties was examined by use of linear regression. One-way analysis of variance was performed to compare differences in the mechanical properties across failure locations.

During cyclic testing, tendon elongation averaged 1.4% ± 1.6% with a CV of 118%. During failure testing, the maximum stress averaged 12.2 ± 4.1 MPa, maximum strain averaged 21.0% ± 6.3%, and modulus of elasticity averaged 95.5 ± 30.8 MPa. The CVs for maximum stress, maximum strain, and modulus of elasticity were 34%, 30%, and 32%, respectively. Ten tendons failed in the midsubstance and 5 failed at the tendon-bone enthesis. No differences were noted in mechanical properties between grafts that failed in the midsubstance versus those that failed at the enthesis. Donor age did not correlate with allograft elongation during cyclic load or any of the material property measures during failure testing.

The variabilities in the material properties and graft elongation during cyclic loading of Achilles tendon allografts used in ACLR fall within the range of properties reported in the literature for other ACLR allografts. Material properties do not differ by donor age or graft failure location observed during failure testing.

Surgeons should be aware that there exists considerable variation in the mechanical properties of Achilles allograft tendons used for ACLR. This variability is difficult to detect by tissue bank screening or the treating surgeon’s inspection and may contribute to the heterogeneity in outcomes of allograft ACLR.

Measuring the size of the anterior cruciate ligament (ACL) tibial footprint on magnetic resonance image (MRI) is common for preoperative planning of ACL reconstruction. However, the accuracy of such measurement has not been well documented.

To investigate whether the actual size of the ACL tibial footprint could be predicted by its measurement on MRI and to develop equations to improve the accuracy of predicting the actual size based on MRI measurement.

Cohort study (diagnosis); Level of evidence, 2.

A total of 164 patients with normal visualized ACL in gross evaluation and MRI were included (mean ± SD age, 67.3 ± 8.3 years). Cases with ACL tear, severe mucoid degeneration, osteophyte around the ACL tibial insertion, or intervals >12 months between MRI and actual measurement were excluded. The ACL tibial footprint was carefully dissected and measured during total knee arthroplasty. The length of the ACL tibial footprint on MRI was measured on a sagittal image, while the width was measured on an oblique coronal image. For the ACL tibial footprint, the association between measurement on MRI and actual measurement of length and width was analyzed via univariable and multivariable regression analyses. Reliability of measurements on MRI was also evaluated.

The length and width of the ACL tibial footprint as measured on MRI showed strong correlation with the actual length and width (coefficients: ρ = 0.904 and ρ = 0.808, respectively). There were differences between ACL size on MRI and its actual size: length, 12.4 mm (range, 9.7-15.3 mm) vs 13.8 (10.6-17.8) (P < .001); width, 8.8 mm (range, 7.0-12.1 mm) vs 7.2 (5.8-10.4) (P < .001). Based on sex, there were also differences between the size per MRI and the actual size (P < .001 for all): length in men, 12.6 mm (range, 10.9-15.3 mm) vs 14.2 (12.3-17.8); length in women, 12.4 mm (range, 9.7-14.5 mm) vs 13.7 (10.6-15.8); width in men, 9.3 mm (range, 8.0-12.1 mm) vs 7.6 (5.8-10.4); width in women, 8.7 mm (range, 7.0-10.4 mm) vs 7.2 (5.8-9.7). The actual length of the ACL tibial footprint could be predicted by its length on MRI and sex (R² = 0.83, P < .001). Similarly, actual width could be predicted by the width on MRI and sex (R² = 0.75, P < .001). All intraclass correlation coefficients were >0.8, indicating good reliability.

Measurements of the size of the ACL tibial footprint on MRI showed strong correlation with its actual size. Prediction equations showed good concordance correlation coefficients.

Off-track Hill-Sachs lesions have been associated with high rates of recurrent shoulder instability. Both arthroscopic Bankart with remplissage and modified Latarjet have been described to treat off-track Hill-Sachs lesions. However, few comparative studies exist between the 2 techniques in heterogeneous populations.

Remplissage would have similar recurrence rates and clinical outcomes to modified Latarjet for off-track Hill-Sachs lesions with subcritical glenoid bone loss.

Cohort study; Level of evidence, 3.

Between 2005 and 2015, 189 patients with recurrent anterior shoulder instability, off-track Hill-Sachs lesion, and less than 25% glenoid bone loss were identified. Arthroscopic Bankart with remplissage (group A) was performed in 98 patients, and modified Latarjet (group B) was performed in 91 patients. Surgeries were performed by multiple fellowship-trained surgeons at 2 centers. The mean follow-up time was 3.2 years. Patients were assessed for their risk of recurrence using the Instability Severity Index Score and had preoperative 3-dimensional imaging to assess humeral and glenoid bone loss, along with measurement of the glenoid track. Single Assessment Numeric Evaluation (SANE), Western Ontario Shoulder Instability Index (WOSI), visual analog scale (VAS) for pain, range of motion, recurrence rate, subsequent procedures, and complications were analyzed.

When comparing the remplissage and Latarjet groups, the remplissage group had a higher VAS pain score (2.2 vs 1.55, P = .041) and less internal rotation motion in abduction (40.9° vs 53.2°, P = .006). The complication rate was higher in the Latarjet group (12.1% vs 1%, P = .002). There was no difference between the 2 groups in patient-reported outcomes, such as WOSI and SANE. In addition, there was no difference between the 2 groups in revision rate and episodes of recurrent instability. In subgroup univariate analysis of revision patients, the remplissage group had higher VAS pain score (3.6 vs 2.2, P = .001), higher recurrence rate (34.8% vs 10.3%, P = .042), higher revision rate (43.5% vs 15.4%, P = .019), and lower complication rate (4.35% vs 28.2%, P = .024). For patients with >15% glenoid bone loss, Latarjet had lower recurrence rate (6.06% vs 28.6%, P = .034) and lower revision rate (3.03% vs 21.4%, P = .041). In collision and contact athletes, Latarjet had better WOSI scores (138 vs 231, P = .019) and lower recurrence rate (30% vs 0%, P = .005). In multivariate analysis, the odds of recurrence in the remplissage group were higher than in the Latarjet group in patients with previous instability surgery (3.56, P = .006), collision and contact athletes (2.37, P = .02), those with 10% to 15% glenoid bone loss (1.28, P = .04), and those with >15% glenoid bone loss (6.48, P = .001).

For off-track Hill-Sachs lesions with subcritical glenoid bone loss, both the remplissage and modified Latarjet can achieve satisfactory results with the initial surgical intervention in the general population, but a higher complication rate was observed in the Latarjet group. However, Latarjet appears to be a better choice in patients with revision instability surgery, collision and contact athletes, and those with >10% glenoid bone loss.

The critical shoulder angle (CSA) is the angle created between the superior and inferior bone margins of the glenoid and the most lateral border of the acromion. A few studies recently investigated the relation between CSA and functional outcomes after rotator cuff repair. However, there is a lack of research investigating the effect of CSA on postoperative tendon integrity after rotator cuff repair.

To assess the effects of the CSA on postoperative tendon integrity after rotator cuff repair.

Cohort study; Level of evidence, 3.

All patients who underwent rotator cuff repair for full-thickness supraspinatus tears by 1 senior surgeon between January 2010 and January 2014 were included in this study. All patients had standardized anteroposterior shoulder radiographs the day before surgery. CSA and acromial index (AI) were measured. AI was derived by measuring the distance from the glenoid plane to the lateral border of the acromion and dividing it by the distance from the glenoid plane to the lateral aspect of the humeral head. Functional scores—including American Shoulder and Elbow Surgeons shoulder evaluation form, modified University of California at Los Angeles score, Constant-Murley score, and visual analog scale for pain—were used to evaluate shoulder function at a minimum follow-up of 2 years. Meanwhile, magnetic resonance imaging examinations were performed to evaluate rotator cuff integrity according to the Sugaya method and the signal/noise quotient (SNQ) of the rotator cuff tendon.

A total of 90 patients were included in this study: 42 patients with a single-row repair and 48 with a double-row repair. There was a significant positive correlation between CSA or AI and tendon SNQ. On the basis of CSA, the patients were divided into 2 groups: large CSA (>38°) and control (CSA ≤38°). At final follow-up, the large CSA group and the control CSA group demonstrated no significant differences in American Shoulder and Elbow Surgeons, University of California at Los Angeles, Constant, and visual analog scale scores. Postoperative magnetic resonance imaging revealed that the large CSA group had 9 cases of retear, with a significantly higher retear rate than the control group (15% vs 0%, P = .03). Furthermore, the tendon SNQ of the large CSA group was significantly greater than that of the control group.

CSA did not appear to influence postoperative functional outcomes, while those in the large CSA group had poor tendon integrity after rotator cuff repair. These findings indicate that a large CSA is associated with an increased risk of rotator cuff tendon retear after repair.

The failure of rotator cuffs to heal after repair is an unresolved surgical issue. There have been substantial efforts, including the use of biological supplements, to enhance tendon healing. Dermal fibroblasts are a good candidate for tendon tissue engineering because they are similar to the tenocytes used for collagen synthesis. In addition, they are easily accessible because autologous dermal fibroblasts can be obtained from individual skin without major skin defects and allogenic dermal fibroblasts (ADFs) have already been commercialized in the field of skin engineering.

To determine the effects of dermal fibroblasts on tendon-to-bone healing in a rabbit model of a chronic rotator cuff tear.

Controlled laboratory study.

A total of 33 rabbits were randomly allocated into 3 groups (n = 11 each). Supraspinatus tendons were detached and left for 6 weeks to establish a chronic rotator tear model. Torn tendons were repaired in a transosseous manner with the injection of 5 × 10⁶ ADFs with fibrin in group A, fibrin only in group B, and saline only in group C. At 12 weeks after repair, the mechanical test and histological evaluation were performed.

Seven rabbits died before the evaluation (1 in group A, 2 in group B, 4 in group C). In the final evaluation, the mean ± SD load to failure was 48.1 ± 13.3 N/kg for group A, 34.5 ± 8.9 N/kg for group B, and 31.1 ± 8.3 N/kg for group C, and group A showed significantly higher load-to-failure values than the other groups (P = .011). The midsubstance tear rate, which presented stronger tendon-to-bone healing than insertional tear, was 50.0% in group A, 22.2% in group B, 28.6% in group C, but the differences were not statistically significant (P = .413). In the histological evaluation, group A showed greater collagen fiber continuity and better orientation than the other groups.

This controlled laboratory study verified, on the basis of biomechanics and histology, the potential for the use of ADFs in rotator cuff healing. The current results suggest a new biological supplement to increase the rate of rotator cuff healing.

The most important finding of this study was the potential for a new biological supplement to enhance rotator cuff healing—a continuing challenge.

Few studies have reported on the radiological characteristics and repair integrity of coexistent rotator cuff tears (RCTs) and shoulder stiffness after simultaneous arthroscopic rotator cuff repair and capsular release.

To evaluate the radiological characteristics and repair integrity of 1-stage arthroscopic surgery of RCTs concomitant with shoulder stiffness.

Cohort study; Level of evidence, 3.

Among patients who underwent arthroscopic repair of full-thickness RCTs, the stiff group underwent simultaneous capsular release for shoulder stiffness, and the nonstiff group had no stiffness. Symptom duration, prevalence of diabetes, tear size, tendon involvement (type 1, supraspinatus; type 2, supraspinatus and subscapularis; and type 3, supraspinatus and infraspinatus; type 4, supraspinatus, subscapularis, and infraspinatus), and fatty infiltration (Goutallier stages 0-4) were evaluated. A retear was appraised using magnetic resonance imaging, and clinical outcomes were assessed using range of motion, the Korean Shoulder Scoring System (KSS), and the University of California, Los Angeles (UCLA) shoulder score.

The stiff group showed a significantly lower retear rate (1/39, 2.6%) than the nonstiff group (47/320, 14.7%) (P = .043). There were significant differences in symptom duration (7.4 ± 6.6 vs 15.0 ± 23.7 months, respectively; P < .001), mediolateral tear size (18.9 ± 8.9 vs 24.1 ± 12.0 mm, respectively; P = .002), tendon involvement (94.9%, 5.1%, 0.0%, and 0.0% vs 85.3%, 6.9%, 7.8%, and 0.0%, respectively; P = .048), and fatty infiltration of the subscapularis (66.7%, 33.3%, 0.0%, 0.0%, and 0.0% vs 31.9%, 61.3%, 5.6%, 1.3%, and 0.0%, respectively; P < .001) and teres minor (74.4%, 20.5%, 5.1%, 0.0%, and 0.0% vs 47.2%, 48.8%, 3.8%, 0.0%, and 0.3%, respectively; P = .007) between the stiff and nonstiff groups. Preoperatively, the stiff group showed significantly worse forward flexion (95.9° ± 23.6° vs 147.7° ± 4.2°, respectively; P < .001), external rotation (17.4° ± 10.1° vs 51.6° ± 12.1°, respectively; P < .001), and internal rotation (L5 vs L2, respectively; P < .001) and lower KSS (52.1 ± 13.8 vs 66.3 ± 13.5, respectively; P < .001) and UCLA scores (18.7 ± 4.8 vs 22.5 ± 4.5, respectively; P < .001) than the nonstiff group. However, these differences became insignificant from 3 months postoperatively for forward flexion (P > .05) and KSS (P > .05) and UCLA scores (P > .05), from 1 year postoperatively for external rotation (P > .05), and at the last follow-up for internal rotation (P > .05). A multiple logistic regression analysis revealed that only mediolateral tear size (odds ratio, 1.043; P = .014) and type 2 tendon involvement (odds ratio, 4.493; P = .003) were independent predictors of a retear.

RCTs concomitant with shoulder stiffness showed a smaller mediolateral tear size, anterosuperior tendon involvement, and less severe fatty infiltration preoperatively and better repair integrity postoperatively than RCTs without stiffness. Furthermore, the clinical outcomes and range of motion at final follow-up were similar between the 2 groups.

Previous biomechanical studies regarding deltoid function during glenohumeral abduction have primarily used static testing protocols.

(1) Deltoid forces required for scapular plane abduction increase as simulated rotator cuff tears become larger, and (2) maximal abduction decreases despite increased deltoid forces.

Controlled laboratory study.

Twelve fresh-frozen cadaveric shoulders with a mean age of 67 years (range, 64-74 years) were used. The supraspinatus and anterior, middle, and posterior deltoid tendons were attached to individual shoulder simulator actuators. Deltoid forces and maximum abduction were recorded for the following tear patterns: intact, isolated subscapularis (SSC), isolated supraspinatus (SSP), anterosuperior (SSP + SSC), posterosuperior (infraspinatus [ISP] + SSP), and massive (SSC + SSP + ISP). Optical triads tracked 3-dimensional motion during dynamic testing. Fluoroscopy and computed tomography were used to measure critical shoulder angle, acromial index, and superior humeral head migration with massive tears. Mean values for maximum glenohumeral abduction and deltoid forces were determined. Linear mixed-effects regression examined changes in motion and forces over time. Pearson product-moment correlation coefficients (r) among deltoid forces, critical shoulder angles, and acromial indices were calculated.

Shoulders with an intact cuff required 193.8 N (95% CI, 125.5 to 262.1) total deltoid force to achieve 79.8° (95% CI, 66.4° to 93.2°) of maximum glenohumeral abduction. Compared with native shoulders, abduction decreased after simulated SSP (–27.2%; 95% CI, –43.3% to –11.1%, P = .04), anterosuperior (–51.5%; 95% CI, –70.2% to –32.8%, P < .01), and massive (–48.4%; 95% CI, –65.2% to –31.5%, P < .01) cuff tears. Increased total deltoid forces were required for simulated anterosuperior (+108.1%; 95% CI, 68.7% to 147.5%, P < .01) and massive (+57.2%; 95% CI, 19.6% to 94.7%, P = .05) cuff tears. Anterior deltoid forces were significantly greater in anterosuperior (P < .01) and massive (P = .03) tears. Middle deltoid forces were greater with anterosuperior tears (P = .03). Posterior deltoid forces were greater with anterosuperior (P = .02) and posterosuperior (P = .04) tears. Anterior deltoid force was negatively correlated (r = −0.89, P = .01) with critical shoulder angle (34.3°; 95% CI, 32.0° to 36.6°). Deltoid forces had no statistical correlation with acromial index (0.55; 95% CI, 0.48 to 0.61). Superior migration was 8.3 mm (95% CI, 5.5 to 11.1 mm) during testing of massive rotator cuff tears.

Shoulders with rotator cuff tears require considerable compensatory deltoid function to prevent abduction motion loss. Anterosuperior tears resulted in the largest motion loss despite the greatest increase in deltoid force.

Rotator cuff tears place more strain on the deltoid to prevent abduction motion loss. Fatigue or injury to the deltoid may result in a precipitous decline in abduction, regardless of tear size.

Anatomic reconstruction techniques are increasingly used to address cases of acromioclavicular (AC) joint chronic instability. These usually involve an additional surgical site for autograft harvesting or an allograft.

To describe a triple-bundle (TB) anatomic reconstruction using on-site autografts, the semiconjoint tendon (SCT) and the coracoacromial ligament (CAL), and compare its primary stability to the native AC joint ligamentous complex and to a modified Weaver-Dunn (WD) reconstruction.

Controlled laboratory study.

Intact AC joints of 12 paired cadaveric shoulders were tested for anterior, posterior, and superior translations under cyclic loading with a servo-hydraulic testing system. One shoulder from each pair was randomly assigned to the TB group, where 2 SCT strips were used to reconstruct the coracoclavicular ligaments while the distal end of the CAL was transferred to the distal extremity of the clavicle to reconstruct the AC ligaments; the other shoulder received a modified WD reconstruction. After reconstruction, the same translational testing was performed, with an additional load-to-failure test in the superior direction.

In both the TB and the WD groups, no significant differences were found before and after reconstruction in terms of joint displacements after cyclic loading, in all 3 directions. Compared with the WD reconstruction, the TB repair resulted in significantly lower displacements in both the anterior (ie, 2.59 ± 1.08 mm, P = .011) and posterior (ie, 10.17 ± 6.24 mm, P = .014) directions, but not in the superior direction. No significant differences were observed between the 2 reconstructions during the load-to-failure testing, except for the displacement to failure, which was significantly smaller (ie, 5.34 ± 2.97 mm) in the WD group (P = .037).

Anterior, posterior, and superior displacements after an anatomic reconstruction of the AC joint complex using the SCT and CAL as graft material were similar to those of native AC joints and significantly smaller in the axial plane than those of AC joints after a WD repair.

An anatomic reconstruction is achievable using the CAL and the SCT as on-site graft materials, providing satisfactory initial stability and thereby allowing earlier mobilization.

Examination of the incidence of shoulder season-ending injury (SEI) in the collegiate athlete population is limited.

To determine the incidence of shoulder SEI in the National Collegiate Athletic Association (NCAA) and to investigate the risk factors for a shoulder injury ending an athlete’s season.

Descriptive epidemiology study.

All shoulder injuries from the NCAA Injury Surveillance Program database for the years 2009-2010 to 2013-2014 were extracted, and SEI status was noted. The incidences of SEI and non-SEI were calculated for athlete, activity, and injury characteristics and compared via univariable analysis and risk ratios to determine risk factors for an injury being season ending.

Shoulder injuries were season ending in 4.3% of cases. The overall incidence of shoulder SEI was 0.31 per 10,000 athlete exposures (AEs), as opposed to 7.25 per 10,000 AEs for all shoulder injuries. Shoulder instability constituted 49.1% of SEI, with an incidence of 0.15 per 10,000 AEs, while fractures had the highest rate of being season ending (41.9%). Men’s wrestling had the highest incidence of shoulder SEI (1.65 per 10,000 AEs), while men’s soccer had the highest proportion of shoulder injuries that ended a season (14.6%). Overall, men had a 6.3-fold higher incidence of SEI than women and a 2.4-fold increased likelihood that an injury would be season ending.

Injury to the shoulder of an NCAA athlete, while somewhat infrequent, can have significant implications on time lost from play. Incidence of these injuries varies widely by sport and injury, with a number of associated risk factors. Athletes sustaining potentially season-ending shoulder injuries, with their coaches and medical providers, may benefit from these data to best manage expectations and outcomes.

Autologous osteochondral mosaicplasty (ie, mosaicplasty) results in satisfactory clinical outcomes and reliable return to play for patients with large or unstable lesions due to osteochondritis dissecans (OCD) of the humeral capitellum. However, the association between the healing of the reconstructed cartilage and clinical outcomes remains unclear.

To evaluate the efficacy of mosaicplasty in teenage athletes through use of clinical scores and imaging. The secondary purpose was to compare the clinical outcomes with images of centrally and laterally located lesions.

Case series; Level of evidence, 4.

This study analyzed 22 elbows (all male patients; mean age, 13.5 ± 1.2 years) with capitellar OCD managed with mosaicplasty. Patients were divided into 2 groups according to the location of the lesions: central (10 patients) and lateral (12 patients). Evaluation was performed through use of the clinical rating system of Timmerman and Andrews, plain radiographs, and magnetic resonance imaging (MRI; the cartilage repair monitoring system of Roberts). The mean follow-up period was 27.5 months (range, 24-48 months).

Lateral lesions were significantly larger than central lesions (147.1 ± 51.9 mm² vs 95.5 ± 27.4 mm², P = .01). No other significant differences were found between central and lateral lesions. Timmerman and Andrews scores for both central and lateral lesions improved significantly from 125.0 ± 30.1 points and 138.3 ± 34.5 points preoperatively to 193.5 ± 11.3 points and 186.7 ± 18.1 points, respectively, at final follow-up (P < .0001, P < .0001). Radiography identified complete graft incorporation in all cases and the absence of severe osteoarthritic changes or displaced osteochondral fragments. In the lateral group, the radial head ratio at final follow-up (1.83 ± 0.23) was significantly larger than the preoperative findings (1.75 ± 0.14, P = .049). The quality of joint surface reconstruction was found to be acceptable for central and lateral lesions on MRI evaluation.

Mosaicplasty resulted in satisfactory clinical outcomes and smooth cartilage surface integrity in teenage athletes with OCD on their return to competition-level sports activities irrespective of lesion location.

Restoring footprint anatomy, minimizing gap formation, and maximizing the strength of distal triceps tendon repairs are essential factors for a successful healing process and return to sport.

The novel V-shaped distal triceps tendon repair technique with unicortical button fixation closely restores footprint anatomy, provides minimal gap formation and high ultimate failure load, and minimizes iatrogenic fracture risk in acute/subacute distal triceps tendon tears.

Controlled laboratory study.

Twenty-four cadaveric elbows (mean ± SD age, 66 ± 5 years) were randomly assigned to 1 of 3 repair groups: the transosseous cruciate repair technique (gold standard), the knotless suture-bridge repair technique, and the V-shaped distal triceps tendon repair technique. Anatomic measurements of the central triceps tendon footprint were obtained in all specimens with a 3-dimensional digitizer before and after the repair. Cyclic loading was performed for a total of 1500 cycles at a rate of 0.25 Hz, pulling in the direction of the triceps. Displacements were measured on the medial and lateral tendon sites with 2 differential variable reluctance transducers. Load to failure and construct failure mode were recorded.

The mean triceps bony insertion area was 399.05 ± 81.23 mm². The transosseous cruciate repair technique restored 36.6% ± 16.8% of the native tendon insertion area, which was significantly different when compared with the knotless suture-bridge repair technique (85.2% ± 14.8%, P = .001) and the V-shaped distal triceps tendon repair technique (88.9% ± 14.8%, P = .002). Mean displacement showed no significant difference between the V-shaped distal triceps tendon repair technique (medial side, 0.75 ± 0.56 mm; lateral side, 0.99 ± 0.59 mm) and the knotless suture-bridge repair technique (1.61 ± 0.97 mm and 1.29 ± 0.8 mm) but significance between the V-shaped distal triceps tendon repair technique and the transosseous cruciate repair technique (4.91 ± 1.12 mm and 5.78 ± 0.9 mm, P < .001). Mean peak failure load of the V-shaped distal triceps tendon repair technique (732.1 ± 156.0 N) was significantly higher than that of the knotless suture-bridge repair technique (505.4 ± 173.9 N, P = .011) and the transosseous cruciate repair technique (281.1 ± 74.8 N, P < .001). Mechanism of failure differed among the 3 repairs, with the only olecranon fracture occurring in the knotless suture-bridge repair technique at the level of the lateral row suture anchors.

At time zero, the V-shaped distal triceps tendon repair technique and the knotless suture-bridge repair technique both provided anatomic footprint coverage. Ultimate load to failure was highest for the V-shaped distal triceps tendon repair technique, while gap formation was different only in comparison with the transosseous cruciate repair technique.

The V-shaped distal triceps tendon repair technique provides an alternative procedure to other established repairs for acute/subacute distal triceps tendon ruptures. The reduced repair site motion of the V-shaped distal triceps tendon repair technique and the knotless suture-bridge repair technique at the time of surgery may allow a more aggressive rehabilitation program in the early postoperative period.

The effect of hip arthroscopy on athletic performance compared with preinjury levels for professional athletes in different sports remains unknown. In addition, while return rates have been reported for professional baseball, football, and hockey players, return rates have not been reported for professional basketball players.

Professional athletes in 4 major North American sports would be able to return to their sport and preoperative level of performance at a high rate after arthroscopic hip surgery.

Descriptive epidemiology study.

Major League Baseball (MLB), National Basketball Association (NBA), National Football League (NFL), and National Hockey League (NHL) athletes who underwent hip arthroscopy were identified through a previously reported protocol based on public sources. Successful return to play (RTP) was defined as returning for at least 1 professional regular season game after surgery. Performance scores were calculated by use of previously established scoring systems. Each player served as his own control, with the season prior to surgery defined as baseline. To make comparisons across sports, the authors adjusted for expected season and career length differences between sports and calculated percentage changes in performance.

The authors identified 227 procedures performed on 180 professional athletes between 1999 and 2016. Successful RTP was achieved in 84.6% (192/227) of the procedures. Compared with all other athletes, NBA athletes returned at a similar rate (85.7%, P ≥ .999). NFL offensive linemen returned at a significantly lower rate than all other athletes (61.1%, P = .010). NHL athletes returned at a significantly higher rate than all other athletes (91.8%, P = .048) and demonstrated significantly decreased performance during postoperative season 1 compared with baseline (–35.1%, P = .002). Lead leg surgery for MLB athletes (batting stance for hitters, pitching stance for pitchers) resulted in a 12.7% reduction in hitter performance score (P = .041), a 1.3% reduction in pitcher fastball velocity (P = .004), and a 60.7% reduction in pitch count (P = .007) one season after surgery compared with baseline. Players in nearly every sport demonstrated significant reductions in game participation after surgery.

This study supports the hypothesis that hip arthroscopy in professional athletes is associated with excellent rates of return at the professional level. However, postoperative performance outcomes varied based on sport and position.

The optimal treatment for a medium- or large-sized cartilage lesion is still controversial. Since an ultrapurified alginate (UPAL) gel enhances cartilage repair in animal models, this material is expected to improve the efficacy of the current treatment strategies for cartilage lesions.

The bone marrow stimulation technique (BMST) augmented by UPAL gel can induce hyaline-like cartilage repair.

Controlled laboratory study.

Two cylindrical osteochondral defects were created in the patellar groove of 27 beagle dogs. A total of 108 defects were divided into 3 groups: defects without intervention (control group), defects with the BMST (microfracture group), and defects with the BMST augmented by implantation of UPAL gel (combined group). At 27 weeks postoperatively, macroscopic and histological evaluations, micro–computed tomography assessment, and mechanical testing were performed for each reparative tissue.

The defects in the combined group were almost fully covered with translucent reparative tissues, which consisted of hyaline-like cartilage with well-organized collagen structures. The macroscopic score was significantly better in the combined group than in the control group (P < .05). The histological scores in the combined group were significantly better than those in the control group (P < .01) and microfracture group (P < .05). Although the repaired subchondral bone volumes were not influenced by UPAL gel augmentation, the mechanical properties of the combined group were significantly better than those of the microfracture group (P < .05).

The BMST augmented by UPAL gel elicited hyaline-like cartilage repair that had characteristics of rich glycosaminoglycan and matrix immunostained by type II collagen antibody in a canine osteochondral defect model. The present results suggest that the current technique has the potential to be one of the autologous matrix-induced chondrogenesis techniques of the future and to expand the operative indications for the BMST without loss of its technical simplicity.

The data support the clinical reality of 1-step minimally invasive cartilage-reparative medicine with UPAL gel without harvesting donor cells.

Platelet-rich plasma (PRP) contains various cytokines and growth factors that may be beneficial to the healing process of injured muscle. Based on the authors’ previous study, PRP releasate can promote proliferation and migration of skeletal muscle cells in vitro, so animal studies are performed to support the use of PRP to treat muscle injury in vivo.

To investigate the effect of PRP releasate on regeneration of injured muscle, as well as its effect on inflammatory reaction and cell apoptosis, in the early stages of the muscle-healing process.

Controlled laboratory study.

The gastrocnemius muscles of Sprague-Dawley rats were injured by partial transverse incision and then treated with PRP releasate. Hematoxylin and eosin stain was used to evaluate the healing process of injured muscle at 2, 5, and 10 days after injury. TUNEL assay was used to evaluate the cell apoptosis of injured muscle after PRP releasate treatment. Immunohistochemistry was used to stain the CD68-positive cells during the healing process. Muscle contractile properties, including fast-twitch and tetanic strength, were evaluated by electric stimulation.

The results revealed that PRP releasate treatment could enhance the muscle-healing process and decrease CD68-positive cells and apoptotic cells. Furthermore, the tetanic strength was significantly higher in injured muscle treated with PRP releasate.

In conclusion, PRP releasate could enhance the healing process of injured muscle and decrease inflammatory cell infiltration as well as cell apoptosis.

PRP promotes skeletal muscle healing in association with decreasing inflammation and apoptosis of injured skeletal muscle. These findings provide in vivo evidence to support the use of PRP to treat muscle injury.

Application of the chondrogenic transforming growth factor beta (TGF-β) is an attractive approach to enhance the intrinsic biological activities in damaged articular cartilage, especially when using direct gene transfer strategies based on the clinically relevant recombinant adeno-associated viral (rAAV) vectors.

To evaluate the ability of an rAAV–TGF-β construct to modulate the early repair processes in sites of focal cartilage injury in minipigs in vivo relative to control (reporter lacZ gene) vector treatment.

Controlled laboratory study.

Direct administration of the candidate rAAV–human TGF-β (hTGF-β) vector was performed in osteochondral defects created in the knee joint of adult minipigs for macroscopic, histological, immunohistochemical, histomorphometric, and micro–computed tomography analyses after 4 weeks relative to control (rAAV-lacZ) gene transfer.

Successful overexpression of TGF-β via rAAV at this time point and in the conditions applied here triggered the cellular and metabolic activities within the lesions relative to lacZ gene transfer but, at the same time, led to a noticeable production of type I and X collagen without further buildup on the subchondral bone.

Gene therapy via direct, local rAAV–hTGF-β injection stimulates the early reparative activities in focal cartilage lesions in vivo.

Local delivery of therapeutic (TGF-β) rAAV vectors in focal defects may provide new, off-the-shelf treatments for cartilage repair in patients in the near future.

Although batters are frequently hit by pitch (HBP) in baseball, the effect of HBP injuries remains undefined in the literature.

To determine the effect of HBP injuries in terms of time out of play, injury patterns resulting in the greatest time out of play, and the value of protective gear such as helmets and elbow pads.

Descriptive laboratory study.

Based on the Major League Baseball (MLB) Health and Injury Tracking System, all injuries to batters HBP during the 2011-2015 MLB and Minor League Baseball (MiLB) seasons were identified and analyzed. Video analysis was performed on all HBP events from the 2015 MLB season. Multivariate stepwise regression analysis was utilized to determine the predictive capacity of multiple variables (velocity, pitch type, location, etc) on injury status and severity.

A total of 2920 HBP injuries resulted in 24,624 days missed (DM) over the 5 seasons. MLB HBP injuries occurred at a rate of 1 per 2554 plate appearances (1 per 9780 pitches thrown). Mean DM per injury were 8.4 (11.7 for MLB vs 8.0 for MiLB, P < .001). Surgery was required for 3.1% of MLB injuries and 1.2% of MiLB injuries (P = .005). The most common body regions injured were the hand/fingers (n = 638, 21.8%), head/face (n = 497, 17.0%), and elbow (n = 440, 15.7%), and there were 146 (5.0%) concussions. Injury rates and mean DM correlated with velocity in a near linear fashion. Players hit in the head/face (odds ratio, 28.7) or distal upper extremity (odds ratio, 6.4) were more likely to be injured than players HBP in other locations. Players with an unprotected elbow missed 1.7 more days (95% CI, –4.1 to 7.6) than those with an elbow protector (P = .554) when injured after being HBP.

Although HBP injuries occur infrequently in the course of normal play, they collectively represent a significant source of time out of play. The most common body regions injured include the hands/fingers and head/face, and batters hit in these locations are significantly more likely to be injured. After contusions, concussions were the most common injury diagnosis.

The Vestibular/Ocular Motor Screening (VOMS) and King-Devick (K-D) test are tools designed to assess ocular or vestibular function after a sport-related concussion.

To determine the test-retest reliability and rate of false-positive results of the VOMS and K-D test in a healthy athlete sample.

Cohort study (diagnosis); Level of evidence, 2.

Forty-five healthy high school student-athletes (mean age, 16.11 ± 1.43 years) completed self-reported demographics and medical history and were administered the VOMS and K-D test during rest on day 1 (baseline). The VOMS and K-D test were administered again once during rest (prepractice) and once within 5 minutes of removal from sport practice on day 2 (removal). The Borg rating of perceived exertion scale was administered at removal. Intraclass correlation coefficients were used to determine test-retest reliability on the K-D test and the average near point of convergence (NPC) distance on the VOMS. Level of agreement was used to examine VOMS symptom provocation over the 3 administration times. Multivariate base rates were used to determine the rate of false-positive results when simultaneously considering multiple clinical cutoffs.

Test-retest reliability of total time on the K-D test (0.91 [95% CI, 0.86-0.95]) and NPC distance (0.91 [95% CI, 0.85-0.95]) was high across the 3 administration times. Level of agreement ranged from 48.9% to 88.9% across all 3 times for the VOMS items. Using established clinical cutoffs, false-positive results occurred in 2% of the sample using the VOMS at removal and 36% using the K-D test.

The VOMS displayed a false-positive rate of 2% in this high school student-athlete cohort. The K-D test’s false-positive rate was 36% while maintaining a high level of test-retest reliability (0.91). Results from this study support future investigation of VOMS administration in an acutely injured high school athletic sample. Going forward, the VOMS may be more stable than other neurological and symptom report screening measures and less vulnerable to false-positive results than the K-D test.

Posttraumatic osteoarthritis (PTOA) after anterior cruciate ligament (ACL) reconstruction ultimately translates into a large economic effect on the health care system owing to the young ages of this population.

The purposes were to perform a meta-analysis to determine the prevalence of osteoarthritis after an ACL reconstruction, examining the effects of length of time after surgery, preoperative time interval from injury to surgery, and patient age at the time of surgery. It was hypothesized that the prevalence of PTOA increased with time from surgery and that increased time from injury to surgery and age were also risk factors for the development of PTOA.

Meta-analysis.

A meta-analysis of the prevalence of radiographic PTOA after ACL reconstruction was performed of studies with a minimum of 5 years’ follow-up, with a level of evidence of 1, 2, or 3. The presence of osteoarthritis was defined according to knee radiographs evaluated with classification based on Kellgren and Lawrence, Ahlbäck, International Knee Documentation Committee, or the Osteoarthritis Research Society International. Metaregression models quantified the relationship between radiographic PTOA prevalence and the mean time from injury to surgery, mean patient age at time of surgery, and mean postoperative follow-up time.

Thirty-eight studies (4108 patients) were included. Longer postsurgical follow-up time was significantly positively associated with a higher proportion of PTOA development. The model-estimated proportion of PTOA (95% CI) at 5, 10, and 20 years after surgery was 11.3% (6.4%-19.1%), 20.6% (14.9%-27.7%), and 51.6% (29.1%-73.5%), respectively. Increased chronicity of the ACL tear before surgery and increased patient age were also associated with a higher likelihood of PTOA development.

The prevalence of osteoarthritis after an ACL reconstruction significantly increased with time. Longer chronicity of ACL tear and older age at the time of surgery were significantly positively correlated with the development of osteoarthritis. A timely referral and treatment of symptomatic patients are vital to diminish the occurrence of PTOA.

There has been a surge in high-level studies investigating platelet-rich plasma (PRP) for tendon and ligament injuries. A number of meta-analyses have been published, but few studies have focused exclusively on tendon and ligament injuries.

To perform a meta-analysis assessing the ability of PRP to reduce pain in patients with tendon and ligament injuries.

Systematic review and meta-analysis.

This study followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A comprehensive search of the literature was carried out in April 2017 using electronic databases PubMed, MEDLINE, and the Cochrane Library. Only level 1 studies were included. Platelet and leukocyte count, injection volume, kit used, participant age/sex, comparator, and activating agent used were recorded. The short-term and long-term efficacy of PRP was assessed using the visual analog scale (VAS) to measure pain intensity. Injury subgroups (rotator cuff, tendinopathy, anterior cruciate ligament, and lateral epicondylitis) were evaluated. Funnel plots and the Egger test were used to screen for publication bias, and sensitivity analysis was performed to evaluate the effect of potential outliers by removing studies one at a time.

Thirty-seven articles were included in this review, 21 (1031 participants) of which could be included in the quantitative analysis. The majority of studies published investigated rotator cuff injuries (38.1%) or lateral epicondylitis (38.1%). Seventeen studies (844 participants) reported short-term VAS data, and 14 studies (771 participants) reported long-term VAS data. Overall, long-term follow-up results showed significantly less pain in the PRP group compared with the control group (weighted mean difference [WMD], –0.84; 95% CI, –1.23 to –0.44; P < .01). Patients treated with PRP for rotator cuff injuries (WMD, –0.53; 95% CI, –0.98 to –0.09; P = .02) and lateral epicondylitis (WMD, –1.39; 95% CI, –2.49 to –0.29; P = .01) reported significantly less pain in the long term. Substantial heterogeneity was reported at baseline (I² = 72.0%; P < .01), short-term follow-up (I² = 72.5%; P < .01), long-term follow-up (I² = 76.1%; P < .01), and overall (I² = 75.8%; P < .01). The funnel plot appeared to be asymmetric, with some missingness at the lower right portion of the plot suggesting possible publication bias.

This review shows that PRP may reduce pain associated with lateral epicondylitis and rotator cuff injuries.