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High-level evidence for short–term outcomes of contemporary anterior cruciate ligament (ACL) suture repair (ACLSR) in comparison with those of ACL reconstruction (ACLR) is scarce. High-level evidence for mid- and long–term results is lacking, whereas outcomes of ACLSR in several historical studies were shown to deteriorate at midterm follow–up after initial good short–term outcomes.
Contemporary ACLSR is noninferior to ACLR in the treatment of acute ACL rupture in terms of patient self–reported outcomes at 5 years postoperatively.
Randomized controlled trial; Level of evidence, 1.
A total of 48 patients were enrolled in the study and, after stratification and randomization, underwent either dynamic augmented (DA) ACLSR or anatomic single–bundle ACLR. The primary outcome measure was the International Knee Documentation Committee 2000 (IKDC) subjective score (IKDCs). Furthermore, the Knee injury and Osteoarthritis Outcome Score (KOOS), Tegner Activity Scale score (TAS), visual analog scale score for satisfaction (VASs), IKDC physical examination score (IKDCpe), limb symmetry index for quadriceps (LSIq) and hamstrings (LSIh) strength and jump test battery (LSIj), Kellgren-Lawrence grade of osteoarthritis (OA), and rate of adverse events were recorded. Analyses were based on an intention–to–treat principle.
The lower limit of the 2–sided 95% CI for the median IKDCs of the DA ACLSR group (n = 23; 75.9) was lower than the prespecified noninferiority margin (n = 21; 86.6). Therefore, the null hypothesis was rejected. However, the upper limit of the 2–sided 95% CI of the DA ACLSR group (100.0) was higher than the median IKDCs of the ACLR group (96.6), rendering the result for noninferiority inconclusive. No statistical difference was found between groups for median IKDCs (repair, 90.2; reconstruction, 96.6). Furthermore, no statistically significant differences were found for any of the secondary outcome measures for the DA ACLSR compared with the ACLR group: KOOS Symptoms, 92.9 versus 96.4; KOOS Pain, 100 versus 97.2; KOOS Activities of Daily Living, 100 versus 100; KOOS Sport and Recreation, 85.0 versus 100; TAS score, 7.0 versus 6.5; VASs, 9.2 versus 8.7; IKDCpe, 81.8% versus 100%; LSIq, ≥91.6 versus ≥88.2; LSIh, ≥95.1 versus ≥90.7; LSIj, ≥94.2 versus ≥97.6; OA grade 0, 90.9% versus 77.8%; clinical ACL failure rate, 20.8% versus 27.2%; and repeat surgery rate, 37.5% versus 20.0%, respectively.
It remains inconclusive whether the effectiveness of DA ACLSR is noninferior to that of ACLR in terms of subjective patient–reported outcomes as measured using the IKDCs. Although DA ACLSR may be a viable treatment option for patients with acute ACL rupture, caution must be exercised when considering this treatment for young, active patients, corresponding to the present study population.
Patients with anterior cruciate ligament (ACL) revision report lower outcome scores on validated knee questionnaires postoperatively compared to cohorts with primary ACL reconstruction. In a previously active population, it is unclear if patient-reported outcomes (PROs) are associated with a return to activity (RTA) or vary by sports participation level (higher level vs. recreational athletes).
Individual RTA would be associated with improved outcomes (ie, decreased knee symptoms, pain, function) as measured using validated PROs. Recreational participants would report lower PROs compared with higher level athletes and be less likely to RTA.
Cohort study; Level of evidence, 2.
There were 862 patients who underwent a revision ACL reconstruction (rACLR) and self-reported physical activity at any level preoperatively. Those who did not RTA reported no activity 2 years after revision. Baseline data included patient characteristics, surgical history and characteristics, and PROs: International Knee Documentation Committee questionnaire, Marx Activity Rating Scale, Knee injury and Osteoarthritis Outcome Score, and the Western Ontario and McMaster Universities Osteoarthritis Index. A binary indicator was used to identify patients with same/better PROs versus worse outcomes compared with baseline, quantifying the magnitude of change in each direction, respectively. Multivariable regression models were used to evaluate risk factors for not returning to activity, the association of 2-year PROs after rACLR surgery by RTA status, and whether each PRO and RTA status differed by participation level.
At 2 years postoperatively, approximately 15% did not RTA, with current smokers (adjusted odds ratio [aOR] = 3.3;
Recreational-level participants were twice as likely to not RTA compared with those participating at higher levels. Within a previously active cohort, no RTA was a significant predictor of lower PROs after rACLR. However, among patients who did RTA after rACLR, approximately 20% reported lower outcome scores. Most patients with rACLR who were active at baseline improved over time; however, patients who reported worse outcomes at 2 years had a clinically meaningful decline across all PROs.
Previous studies have shown a higher prevalence of meniscal and chondral lesions at the time of revision anterior cruciate ligament reconstruction (R-ACLR) compared with primary ACLR procedures. However, studies that follow the development of meniscal and chondral status through primary and subsequent R-ACLR are scarce.
To compare the prevalence of meniscal and chondral injuries in patients undergoing primary ACLR and subsequent R-ACLR.
Case series; Level of evidence, 4.
Patients who underwent ACLR and subsequently needed R-ACLR between January 2009 and February 2018 in a single center were included. A retrospective analysis of prospectively collected data was conducted.
A total of 213 patients were included, with a mean follow-up of 59.7 months. The mean age was 22 years at primary ACLR and 26.1 years at the time of revision. The proportion of meniscal tears was higher at the time of R-ACLR compared with the time of primary reconstruction (70.0% vs 44.6%, respectively;
R-ACLR is associated with a higher rate of concomitant meniscal and chondral lesions than primary ACLR.
Anterolateral structure augmentation (ALSA) has been applied to prevent residual rotatory instability and lower clinical failure rates after anterior cruciate ligament (ACL) reconstruction (ACLR); however, the effect of combined ALSA on the maturity of ACL grafts remains unknown.
To evaluate the graft maturity and patient–reported outcomes in patients who underwent double–bundle ACLR with or without ALSA.
Cohort study; Level of evidence, 3.
A total of 92 patients who underwent double–bundle ACLR between January 2016 and July 2019 were included in the present study—44 patients with isolated ACLR (ACLR group) and 48 patients with combined ACLR and ALSA (ALSA group). Demographic characteristics, intraoperative findings, and patient–reported outcomes were prospectively collected. On postoperative magnetic resonance imaging at the 2–year follow–up, the signal–to–noise quotient (SNQ) values were separately calculated for 6 sections of the ACL graft, including the femoral intratunnel graft (FTG), intra–articular graft (IAG), and tibial intratunnel graft (TTG) of the anteromedial bundle (AMB) and the posterolateral bundle (PLB). Superior graft maturity was usually indicated by lower SNQ values.
The rates of return to preinjury sports were 47.9% and 27.3% in the ALSA and ACLR groups, respectively (difference, 20.6% [95% CI, 1.3%-40%];
A combination of ACLR and ALSA is a desirable option to improve the maturity of ACL grafts for patients who are young or expected to return to pivoting sports. Meanwhile, further investigations with higher levels of evidence and longer periods of follow–up are warranted.
A “Stener-like” lesion of the knee is defined as a distal avulsion of the superficial medial collateral ligament (sMCL) with interposition of the pes anserinus between the ligament and its tibial insertion—a displacement impeding anatomic healing. Because of the scarcity of these injuries, the literature is limited to case reports and small case series.
To assess the effect of surgical repair of acute Stener-like lesions of the sMCL on the following outcomes: return to preinjury level of sporting function; time to return to preinjury level of sporting function; functional performance; injury recurrence; and any other complications.
Case series: Level of evidence, 4.
This prospective single–surgeon study included 23 elite athletes with a mean age of 27.2 years (range, 19-37 years). Of the participants, 20 were men (87%) and 3 were women (13%). The mean body mass index was 23.1 ± 2.3. A total of 16 athletes were soccer players (70%) and 7 were rugby players (30%), with isolated acute, traumatic Stener-like lesions of the sMCL of the knee confirmed on preoperative magnetic resonance imaging. Surgical repair was undertaken with primary suture anchor repair with ligament repair or reconstruction system (LARS) augmentation. Predefined outcomes were recorded at regular intervals after surgery. The minimum follow–up time was 24 months (range, 24-108 months) from the date of surgery.
The mean time from injury to surgical intervention was 9 days (range, 3-28 days). Overall, 15 (65%) athletes had isolated distal sMCL injuries requiring anatomic suture anchor repair at the distal tibial insertion site only, and 8 (35%) athletes had concomitant injuries of the proximal and distal sMCL and required anatomic suture anchor repair at the proximal and distal attachment sites. Ten athletes required LARS augmentation at the time of the index operation. All study patients returned to their preinjury level of sporting activity in professional soccer or rugby. The mean time from surgical intervention to return to full sporting activity was 16.8 ± 2.7 weeks. At 6 and 24 months’ follow–up, all patients had Tegner scores of 10. At a 2–year follow–up, all study patients were still participating at their preinjury level of sporting activity. Three patients developed complications around the LARS that required further surgery to remove synthetic material; however, this did not affect function.
Surgical repair of acute Stener-like lesions of the sMCL is associated with a high return to preinjury level of sporting function, excellent functional performance, and a low risk of recurrence at short–term follow-up in elite athletes.
Although a medial collateral ligament (MCL) injury is associated with anteromedial rotatory instability (AMRI) and often with an anterior cruciate ligament (ACL) injury, there has been little work to develop anteromedial (AM) reconstruction to address this laxity.
To measure the ability of a novel “anatomic” AM reconstruction technique to restore native knee laxity for isolated AM insufficiency and combined AM plus posteromedial insufficiency.
Controlled laboratory study.
A total of 12 cadaveric knees were mounted in a kinematic testing rig that allowed the tibia to be loaded while the knee flexed-extended 0° to 100° with 88-N anteroposterior translation, 5-N·m internal rotation–external rotation (ER), 8-N·m valgus, and combined anterior translation plus ER to simulate AMRI. Joint motion was measured using optical trackers with the knee intact, after superficial MCL (sMCL) and deep MCL (dMCL) transection, and after AM reconstruction of the sMCL and dMCL with semitendinosus autografts. The posteromedial capsule (PMC)/posterior oblique ligament (POL) was then transected to induce a grade 3 medial injury, and kinematic measurements were repeated afterward and again after removing the grafts. Laxity changes were examined using repeated-measures analysis of variance and post-testing.
sMCL and dMCL deficiency increased valgus, ER, and AMRI laxities. These laxities did not differ from native values after AM reconstruction. Additional PMC/POL deficiency did not increase these laxities significantly but did increase internal rotation laxity near knee extension; this was not controlled by AM reconstruction.
AM reconstruction eliminated AMRI after transection of the dMCL and sMCL, and also eliminated AMRI after additional PMC/POL transection.
Many MCL injuries occur in combination with ACL injuries, causing AMRI. These injuries may rupture the AM capsule and dMCL. Unaddressed MCL deficiency leads to an increased ACL reconstruction failure rate. A dMCL construct oriented anterodistally across the medial joint line, along with an sMCL graft, can restore native knee ER laxity. PMC/POL lesions did not contribute to AMRI.
There are many descriptions of medial collateral ligament (MCL) reconstruction, but they may not reproduce the anatomic structures and there is little evidence of their biomechanical performance.
To investigate the ability of “anatomic” MCL reconstruction to restore native stability after grade III MCL plus posteromedial capsule/posterior oblique ligament injuries in vitro.
Controlled laboratory study.
Twelve cadaveric knees were mounted in a kinematic testing rig to impose tibial displacing loads while the knee was flexed-extended: 88-N anteroposterior translation, 5-N·m internal-external rotation, 8-N·m valgus-varus, and combined anterior translation plus external rotation (anteromedial rotatory instability). Joint motion was measured via optical trackers with the knee intact; after superficial MCL (sMCL), deep MCL (dMCL), and posterior oblique ligament transection; and then after MCL double- and triple-strand reconstructions. Double strands reproduced the sMCL and posterior oblique ligament and triple-strands the sMCL, dMCL, and posterior oblique ligament. The sMCL was placed 5 mm posterior to the epicondyle in the double-strand technique and at the epicondyle in the triple-strand technique. Kinematic changes were examined by repeated measures 2-way analysis of variance with posttesting.
Transection of the sMCL, dMCL, and posterior oblique ligament increased valgus rotation (5° mean) and external rotation (9° mean). The double-strand reconstruction controlled valgus in extension but allowed 5° excess valgus in flexion and did not restore external rotation (7° excess). The triple-strand reconstruction restored both external rotation and valgus throughout flexion.
In a cadaveric model, a triple-strand reconstruction including a dMCL graft restored native external rotation, while a double-strand reconstruction without a dMCL graft did not. A reconstruction with the sMCL graft placed isometrically on the medial epicondyle restored valgus rotation across the arc of knee flexion, whereas a reconstruction with a more posteriorly placed sMCL graft slackened with knee flexion.
An MCL injury may rupture the anteromedial capsule and dMCL, causing anteromedial rotatory instability. Persistent MCL instability increases the likelihood of ACL graft failure after combined injury. A reconstruction with an anteromedial dMCL graft restored native external rotation, which may help to unload/protect an ACL graft. It is important to locate the sMCL graft isometrically at the femoral epicondyle to restore valgus across flexion.
Medial meniscal ramp lesion (MMRL), lateral meniscus root tear (LMRT), and anterolateral ligament (ALL) tear are individual injuries that have been described in patients who have an anterior cruciate ligament (ACL) tear. However, the prevalence of these lesions and their combination has not been defined.
To define the individual and combined prevalence of MMRL, LMRT, and ALL tears in a case series of patients undergoing ACL reconstruction and to identify the risk factors for combined injuries.
Cross-sectional study; Level of evidence, 3.
Patients aged >15 years undergoing primary ACL reconstruction between January 2019 and June 2021 were enrolled in the study. A preoperative ultrasound scan was performed to look for an ALL tear. The presence of MMRL and LMRT was determined during a standardized arthroscopy exploration. A multivariate logistic regression model was used to determine the individual effect of patient variables on the risk of associated single, dual, triad, or tetrad injuries (MMRL, LMRT, ALL, ACL), represented by an adjusted odds ratio.
The case series consisted of 602 patients who underwent primary ACL reconstruction. An isolated ACL injury was present in 147 patients (24%). A dual injury was detected in 34 patients (6%) who had ACL-MMRL, 16 (2.65%) who had ACL-LMRT, and 265 (44%) who had ACL-ALL. A triad injury was detected in 80 patients (13.28%) who had ACL-ALL-MMRL, 36 (6%) who had ACL-ALL-LMRT, and 3 (0.5%) who had ACL-MMRL-LMRT. A tetrad injury pattern was detected in 21 patients (3.5%). Multivariate analysis showed that the occurrence of tetrad injury was significantly lower in older patients (adjusted odds ratio by year, 0.93 [95% CI, 0.88-0.99];
Isolated ACL tear is less common than combined injuries, which are quite frequent. Younger age is a risk factor for combined injuries. The search for damaged secondary stabilizers of the knee must be meticulous and systematic, especially when 1 injured structure has already been diagnosed.
Meniscal extrusion/translation has been used as an index for meniscal treatment. However, the relationship between meniscal displacement and the degree of meniscal tear or load–transmission function of the lateral meniscus (LM) remains unclear.
To clarify the relationship between the width of the radial tear of the LM and (1) meniscal displacement or (2) resultant force through the meniscus under axial compressive load in the porcine model.
Controlled laboratory study.
Eight intact porcine knees with or without a partial radial tear at the midbody of the LM (involving 30%, 60%, or 90% of its width) were investigated. Reflective markers were attached to the outer wall of the anterior, anteromiddle, posteromiddle, and posterior segments of the LM. A 300-N axial load was applied at 2 flexion angles (30° and 60°), and the 3–dimensional forces and trajectories of the knees were recorded. Marker movements were simultaneously tracked using a motion capture camera system. After total meniscectomy of the LM, the recorded knee trajectories were reproduced, and the resultant force through the LM was calculated (a force carried only by the meniscus in response to a load applied to the whole knee joint).
At both flexion angles, the change in distance (mean ± SD) between the anterior and posterior markers under load increased significantly more in the anteroposterior direction in LMs with a 90% tear than in intact LMs (30°, 0.4 ± 0.3 vs 1.4 ± 0.8 mm,
LMs with a 90%-width midbody radial tear lost load–transmission function with their displacement relative to the tibia primarily in the anteroposterior direction in the porcine model.
Even 1 mm of displacement after meniscal injury is evidence that the load–transmission function of the meniscus is greatly impaired. When a displaced torn LM is diagnosed in preoperative imaging, meniscal repair surgery should be considered.
Lateral meniscal repair using an all–inside meniscal repair device involves a risk of iatrogenic peroneal nerve injury. To our knowledge, there have been no previous studies evaluating the risk of injury with the knee in the standard operational figure-of-4 position with joint dilatation in arthroscopic lateral meniscal repair.
To evaluate and compare the risk of peroneal nerve injury and establish the safe and danger zones in repairing the lateral meniscus through the anteromedial, anterolateral, or transpatellar portal in relation to the medial and lateral borders of the popliteal tendon (PT).
Descriptive laboratory study.
Using axial magnetic resonance imaging (MRI) studies of knees in the figure-of-4 position with joint fluid dilatation at the level of the lateral meniscus, we drew direct lines to simulate a straight all–inside meniscal repair device deployed from the anteromedial, anterolateral, and transpatellar portals to the medial and lateral borders of the PT. If the line passed through or touched the peroneal nerve, a risk of iatrogenic peroneal nerve injury was noted, and measurements were made to determine the safe and danger zones for peroneal nerve injury in relation to the medial or lateral border of the PT.
Axial MRI images of 29 adult patients were reviewed. Repairing the lateral meniscus through the anteromedial portal in relation to the lateral border of the PT and through the anterolateral portal in relation to the medial border of the PT had a 0% risk of peroneal nerve injury. The “safe zone” in relation to the medial border of the PT through the anterolateral portal was between the medial border of the PT and 9.62 ± 4.60 mm medially from the same border.
It is safe to repair the body of the lateral meniscus through the anteromedial portal in the area lateral to the lateral border of the PT or through the anterolateral portal in the area medial to the medial border of the PT.
There is a risk of iatrogenic peroneal nerve injury during lateral meniscal repair. Thus, we recommend repairing the lateral meniscal tissue through the anteromedial portal in the area lateral to the lateral border of the PT and using the anterolateral portal in the area medial to the medial border of the PT, as neither of these approaches resulted in peroneal nerve injury. Additionally, the surgeon can decrease this risk by repairing the meniscal tissue using the all–inside meniscal device in the safe zone area.
A traumatic lateral patellar dislocation is a common injury in adolescents and young adults. The majority of first–time dislocations can be treated nonoperatively. Various types of knee braces are used for nonoperative treatment, but evidence on the most preferable bracing method is lacking.
To evaluate the efficacy of a patella–stabilizing, motion-restricting knee brace versus a neoprene nonhinged knee brace for the treatment of a first–time traumatic patellar dislocation at 3 years of follow–up.
Randomized controlled trial; Level of evidence, 1.
A total of 101 skeletally mature patients with a first–time traumatic patellar dislocation were enrolled in the study. After exclusion criteria were applied, 79 patients with a first–time traumatic patellar dislocation were randomized and allocated into 2 study groups: group A, with a patella–stabilizing, motion-restricting knee brace (hinged to allow knee range of motion [ROM] of 0°-30°) and group B, with a neoprene nonhinged knee brace (not restricting any knee motion). Both groups received similar physical therapy instructions and were advised to use the brace continuously for 4 weeks. Overall, 64 patients completed the trial.
The redislocation rate in group A was 34.4% (11/32) and in group B it was 37.5% (12/32) (risk difference, –3.1% [95% CI, –26.6% to 20.3%];
The use of a patella–stabilizing, motion-restricting knee brace for 4 weeks after a first–time traumatic patellar dislocation did not result in a statistically significant reduction in redislocations versus a neoprene nonhinged knee brace, although this trial was underpowered to detect more modest differences. Knee immobilization was associated with quadriceps muscle atrophy, less knee ROM, and worse functional outcomes in the first 6 months after the injury.
NCT01344915 (ClinicalTrials.gov identifier).
Comparable short-term outcomes have been obtained using hamstring allografts versus autografts after primary segmental labral reconstruction (SLR). Midterm results have not yet been determined.
(1) To evaluate minimum 5-year patient-reported outcome (PRO) scores in patients who underwent primary SLR with hamstring grafts in the setting of femoroacetabular impingement syndrome (FAIS) and irreparable labral tears and (2) to compare the outcomes of hamstring autografts versus allografts in a subanalysis using propensity-matched groups.
Cohort study; Level of evidence, 3.
Prospectively collected data were retrospectively reviewed for patients who underwent primary hip arthroscopy between September 2010 and November 2015. Patients were included if they underwent SLR using hamstring autografts or allografts and had preoperative and minimum 5-year PROs. The exclusion criteria were previous ipsilateral hip surgery or conditions, dysplasia, or Tönnis grade >1. Patients with autograft SLR were propensity matched 1 to 1 based on age, sex, and body mass index (BMI) to patients who underwent SLR using hamstring allografts. The minimal clinically important difference (MCID) and the Patient Acceptable Symptom State (PASS) were calculated.
Overall, 48 patients (N = hips 48) were eligible to be included in this study, and 41 patients (n = 41 hips [85.4%]) had a minimum 5-year follow-up reporting significant improvements in all PROs. Within the entire cohort, 9.8% required a secondary arthroscopy, with a mean time of 19 ± 1.8 months, and survivorship was 82.9%. Of the 41 included patients, 15 underwent an SLR with a hamstring autograft and were matched to 15 patients with labral reconstruction using a hamstring allograft. Groups were similar for sex (
At a minimum 5-year follow-up, patients who underwent primary arthroscopic SLR in the context of FAIS and irreparable labra, with either autograft or allograft hamstring tendons, reported significant improvements and comparable postoperative scores for all PROs, patient satisfaction, MCID, and PASS.
Hip arthroscopy for femoroacetabular impingement (FAI) in athletes, including military servicemembers, has resulted in variable outcomes. The prevalence of low back pain (LBP) and psychiatric disorders (PSYs) is high among patients undergoing hip arthroscopy.
To determine the effect of LBP, PSYs, and the combination of both on outcomes in servicemembers treated arthroscopically for FAI.
Cohort study; Level of evidence, 2.
Between April 2016 and June 2020, a total of 108 consecutive active-duty servicemembers underwent hip arthroscopy by a single surgeon at a single military medical center. Servicemembers were grouped according to the presence of preoperative LBP (Group LBP), a PSY (Group PSY), or both (Group Both), and outcomes were compared with those of servicemembers without these comorbidities (Group None). The minimum follow-up was 6 months. The primary outcome measure was return to duty (RTD). Secondary outcomes included the Nonarthritic Hip Score (NAHS), Hip Outcome Score–Activities of Daily Living (HOS-ADL) subscale, and Hip Outcome Score–Sports (HOS-S) subscale.
All servicemembers’ final duty status was confirmed, with a mean follow-up of 2 years (range, 6 months–4.3 years). The prevalence of preoperative LBP and PSY was 27% and 39%, respectively. RTD was 59% (10/17) in Group LBP, 10% (3/30) in Group PSY, 0% (0/12) in Group Both, and 47% (23/49) in Group None. Compared with Group None, the risk of discontinuing military service was statistically higher in Group PSY (relative risk [RR], 1.70 [95% CI, 1.41-1.99]) and Group Both (RR, 1.88 [95% CI, 1.62-2.15]) but not in Group LBP (RR, 0.78 [95% CI, 0.15-1.40]). The mean preoperative secondary outcomes all significantly improved postoperatively in Group None (NAHS, 58 to 75 [
Preoperative LBP, PSY, and a combination of both negatively affected outcomes after hip arthroscopy. Preoperative counseling is crucial in setting realistic outcome expectations.
Personalized medicine models to predict outcomes of orthopaedic surgery are scarce. Many have required data that are only available postoperatively, mitigating their usefulness in preoperative decision making.
To establish a method for predictive modeling to enable individualized prognostication and shared decision making based on preoperative patient factors using data from a prospective hip preservation registry.
Cohort study (Prognosis); Level of evidence, 2.
Preoperative data of 2415 patients undergoing hip arthroscopy for femoroacetabular impingement syndrome between February 2008 and November 2017 were retrospectively analyzed. Two machine-learning analyses were evaluated: Tree-structured survival analysis (TSSA) and Cox proportional hazards modeling for predicting time to event and for computing hazard ratios for survivorship after hip arthroscopy. The Fine-Gray model was similarly used for repeat hip arthroscopy. Variables were selected for inclusion using the minimum Akaike Information Criterion (AIC). The stepwise selection was used for the Cox and Fine-Gray models. A web-based calculator was created based on the final models.
Prognostic models were successfully created using Cox proportional hazards modeling and Fine-Gray models for survivorship and repeat hip arthroscopy, respectively. The Harrell C-statistics of the Cox model calculators for survivorship after hip arthroscopy and the Fine-Gray model for repeat hip arthroscopy were 0.848 and 0.662, respectively. Using the AIC, 13 preoperative variables were identified as predictors of survivorship, and 6 variables were identified as predictors for repeat hip arthroscopy. In contrast, the TSSA model performed poorly, resulting in a Harrell C-statistic <0.6, rendering it inaccurate and not interpretable. A web-based calculator was created based on these models.
This study successfully created an institution-specific machine learning–based prognostic model for predictive analytics in patients undergoing hip arthroscopy. Prognostic models to predict survivorship and the need for repeat surgeries were both adapted into web-based tools to assist the physician with shared decision making. This prognostic model may be useful at other institutions after performing external validation. Additionally, this study may serve as proof of concept for a methodology for the development of patient-specific prognostic models. This methodology may be used to create other predictive analytics models in different realms of orthopaedic surgery, contributing to the evolution from evidence-based medicine to personalized medicine.
Favorable short-term outcomes in competitive basketball players have been reported. Midterm outcomes in these athletes and how they compare with athletes in sports with similar demands have not been well established.
(1) To report minimum 5-year patient-reported outcomes (PROs) and return to sports data in competitive basketball players undergoing primary hip arthroscopy for femoroacetabular impingement syndrome (FAIS) and (2) to compare outcomes with a propensity-matched control group of other cutting sports athletes.
Cohort study, Level of evidence, 3.
Data were prospectively collected and retrospectively reviewed for basketball players who competed at the professional, collegiate, high school, or competitive amateur levels and underwent primary hip arthroscopy for FAIS between May 2009 and March 2016. Patients with preoperative and minimum 5-year postoperative outcomes for the modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), Hip Outcome Score–Sports Specific Subscale (HOS-SSS), and visual analog scale (VAS) for pain were included. Patients were propensity matched to athletes in other cutting sports (soccer, lacrosse, field hockey, and tennis) according to age, sex, body mass index (BMI), and preoperative competition level for comparison.
A total of 28 competitive basketball players were included, with a mean follow-up time of 67.1 ± 5.1 months and a mean BMI of 23.7 ± 4; there were 12 (42.9%) female athletes. The cohort was composed of 1 professional, 10 collegiate, 13 high school, and 4 organized amateur athletes. They demonstrated significant improvements in all recorded PROs from baseline to the minimum 5-year follow-up (
Competitive basketball players undergoing primary hip arthroscopy for FAIS demonstrated significant improvements in all recorded PROs and high rates of continued play at a minimum 5-year follow-up. When compared with a control group of other cutting sports athletes, basketball players exhibited more severe ALAD grades intraoperatively but similar midterm outcomes.
Femoroacetabular impingement (FAI) is a leading cause of hip pain in young adults and often leads to degenerative osteoarthritis (OA). A small animal model of hip deformities is crucial for unraveling the pathophysiology of hip OA secondary to FAI.
To (1) characterize a new minimally invasive surgical technique to create a proximal femoral head–neck deformity in a skeletally immature rabbit model and (2) document the effect of an injury to the medial proximal femoral epiphysis on head–neck morphology at 28 days after the injury.
Controlled laboratory study.
Six-week-old New Zealand White rabbits (n = 10) were subjected to right hip surgery, with the left hip used as a control. An epiphyseal injury in the medial femoral head was created using a 1.6-mm drill. Hips were harvested bilaterally at 28 days after surgery. Alpha and epiphyseal shaft angles were measured on radiographs. Alpha angles at the 1- and 3-o’clock positions were measured on the oblique axial plane of micro–computed tomography images. Bone bar formation secondary to growth plate injuries was confirmed using alcian blue hematoxylin staining.
All hips in the study group showed a varus–type head-neck deformity, with lower epiphyseal shaft angles on anteroposterior radiographs versus those in the control group (133°± 8° vs 142°± 5°, respectively;
The proposed model led to growth arrest at the proximal femoral physis, resulting in a femoral head–neck deformity similar to human FAI.
Our novel small animal model of a femoral head–neck deformity is a potential platform for research into the basic mechanisms of FAI disease progression and the development of disease–modifying therapies.
In patients with a known unilateral posterosuperior rotator cuff tear (PSRCT), the ability to predict a contralateral PSRCT may assist in earlier diagnosis and improved patient outcomes.
To determine factors associated with bilateral PSRCT and their most predictive combinations using a nonhospitalized general population.
Cross-sectional study; Level of evidence, 3.
This study involved 736 individuals (n = 1472 shoulders) drawn from a rural cohort. PSRCT was diagnosed using magnetic resonance imaging. Symptoms of the contralateral shoulder were not considered. The demographic, physical, social, metabolic, and imaging factors, as well as comorbidities, were evaluated using logistic regression analysis. Cutoff values for the significantly associated variables obtained from multivariable logistic regression analysis were calculated using the receiver operating characteristic (ROC) curve. The areas under the ROC curve (AUCs) of the combinations of significantly associated variables were compared using the DeLong method to determine the combination most predictive of bilateral PSRCT. The likelihood ratio and the posttest probability for each of the combinations were assessed.
Age ≥61 years, manual labor, critical shoulder angle (CSA) ≥35°, retraction degree of Patte ≥ grade 2, biceps tendon injury, and metabolic syndrome were significantly associated with bilateral PSRCT in multivariable analysis (
Unilateral PSRCT, accompanied by any 4 of the variables of age ≥61 years, manual labor, CSA ≥35°, retraction degree of Patte ≥ grade 2, biceps tendon injury, and metabolic syndrome, is highly predictive of PSRCT in the other shoulder.
Superior capsular reconstruction (SCR) and lower trapezius transfer (LTT) have recently been utilized to treat irreparable rotator cuff tears (IRCTs). There is still no clear guideline on which treatment method is a better fit for posterosuperior IRCTs with high-grade 4 fatty infiltration in the infraspinatus.
To compare the clinical and radiological outcomes between arthroscopic-assisted SCR (aSCR) and arthroscopic-assisted LTT (aLTT) in patients with posterosuperior IRCTs with high-grade (Goutallier grade 4) fatty infiltration in the infraspinatus muscle.
Cohort study; Level of evidence, 3.
This retrospective study included patients who underwent aSCR or aLTT for posterosuperior IRCTs with high-grade 4 fatty infiltration in the infraspinatus and had a minimum follow-up of 2 years between 2017 and 2019. A total of 58 patients were divided into 2 groups according to the surgical procedure: aSCR group (n = 22) and aLTT group (n = 36). Clinical outcomes comprised the visual analog scale score for pain, active shoulder range of motion (ROM), the American Shoulder and Elbow Surgeons (ASES) score, and patient satisfaction. Radiological outcomes comprised the acromiohumeral distance (AHD). The progression of arthritis was evaluated via the Hamada grade. Graft integrity was assessed on postoperative magnetic resonance imaging scans.
Significant improvements in clinical outcomes were observed in both groups. However, active shoulder ROM (forward elevation: 165.7°± 22.3° vs 145.5°± 32.3°, respectively [
Although aSCR and aLTT both provided improvements in overall clinical outcomes for posterosuperior IRCTs with high-grade 4 fatty infiltration in the infraspinatus, aLTT was superior in terms of functional improvement, patient satisfaction, progression of arthritis, and graft integrity. Therefore, we prefer aLTT for posterosuperior IRCTs under the condition of high-grade 4 fatty infiltration in the infraspinatus.
Knotted suture bridge repair (KSBR) has been widely proven to be an effective method for rotator cuff repairs. However, the occurrence of type 2 failure after suture bridge repair remains a frequent problem because of the stress concentration and disturbance of tendon perfusion in the medial row. The authors have developed the H-loop knotless double–row repair (HLDR) to counteract these problems.
To compare the biomechanical and histological outcomes of HLDR and KSBR for rotator cuff tear in the rabbit model.
Controlled laboratory study.
Acute bilateral supraspinatus tears were created on the shoulders of 46 New Zealand White rabbits. HLDR and KSBR were randomly performed on the left side or right side. Thirteen animals each were sacrificed at 2, 4, and 8 weeks after surgery (n = 39), with 6 rabbits used for histological evaluation and the other 7 rabbits for biomechanical testing. The remaining 7 animals from the original 46 were only used for initial biomechanical evaluation at week 0.
Macroscopically, all repaired tendons were connected to their footprint on the greater tuberosity without postoperative complications at 8 weeks after surgery. The HLDR group had significantly better histological bone–to–tendon integration compared with the KSBR group in terms of fibrocartilage regeneration, collagen composition, and fiber organization. The biomechanical outcomes in the HLDR group were demonstrated to be better than those of the KSBR group at time 0 and 8 weeks after surgery.
Both repair techniques were effective for rotator cuff tears in a rabbit rotator cuff tear model; however, HLDR demonstrated more advantages in improving biomechanical properties and histological tendon–to–bone healing compared with KSBR.
This animal study suggested that HLDR might be an alternative choice for rotator cuff tears in humans to increase tendon–to–bone healing and reduce the rate of failure to heal.
Advanced glycation end products (AGEs) are end products of protein glycation that bind to the receptor for AGEs (RAGE) and activate nicotinamide adenine dinucleotide phosphate oxidase (NOX), resulting in increased oxidative stress and rotator cuff fragility. Stump classification using the signal intensity ratio of the tendon rupture site to the deltoid muscle in the coronal view of T2-weighted fat-suppressed magnetic resonance imaging (MRI) scans is an indicator of clinical outcomes after rotator cuff repair surgery. Comparing the signal intensities of the deltoid (D) and rotator cuff tears (C), Ishitani et al. classified C/D <0.8 as type 1, 0.8 to 1.3 as type 2, and >1.3 as type 3.
It was hypothesized that the oxidative stress and collagen degeneration that occur in the rotator cuff due to accumulation of AGEs can be assessed on MRI scans (stump classification). Therefore, this study aimed to compare AGE-related factors in the rotator cuff tear site tissues based on stump classification.
Descriptive laboratory study.
The authors included 30 patients (11 with type 1, 9 with type 2, and 10 with type 3; mean age, 62.3 years) who underwent surgery for complete rotator cuff tears at our hospital. Tendon tissue was harvested from the torn rotator cuff site during surgery for tissue and cell evaluation.
There was no significant difference in the mean age according to stump classification. The number of patients with diabetes was significantly larger in type 3 than in the other types (
Stump classification type 3 exhibited the highest accumulation of AGEs and the highest oxidative stress and apoptosis, suggesting a high degree of degeneration and inflammation. Imaging based on stump classification reflects the degeneration and fragility of the torn rotator cuff site.
This study provides evidence of a relationship between stump classification, which reflects rotator cuff fragility on MRI, and pathologies related to advanced glycation end products.
Although the coracoclavicular (CC) ligaments are classically reconstructed after acromioclavicular (AC) joint injuries, biomechanical studies over the past decade have indicated the importance of an additional reconstruction of the AC ligaments. To date, no kinematic study has investigated the kinematic differences between these reconstruction strategies.
To evaluate the restoration of shoulder motion after an AC injury using a CC ligament, an AC ligament, or a combined reconstruction technique.
Controlled laboratory study.
After creating a Rockwood grade V lesion in 14 cadaveric shoulders, the AC joint injury was treated with either a CC ligament reconstruction using a suspension device, an in situ AC ligament reconstruction using 2 coupled soft tissue anchors, or a combination of these 2 techniques. Joint motions were registered during humerothoracic elevation in the coronal plane and protraction in the intact shoulder in a Rockwood V lesion and after the 3 reconstruction strategies. An optical navigation system measured 3-dimensional rotation in the sternoclavicular and scapulothoracic joints, and both rotation and translation were analyzed in the AC joint.
In the sternoclavicular joint, the CC and combined reconstruction techniques adequately restored clavicular axial rotation, while the AC reconstruction technique showed a better correction of clavicular elevation. Scapulothoracic joint rotations were best restored by reconstructing the AC ligaments. In the AC joint, the relative tilting position and the lateral rotation of the scapula compared with the clavicle were best restored by the suspension device and combined reconstruction. The AC ligament reconstruction technique demonstrated a better restoration of the relative protracted position and resulted in a better correction of the translation of the scapula relative to the clavicle.
This study illustrates that there are kinematic differences between AC, CC, or combined ligament reconstruction strategies. Although each technique was able to restore different elements of the joint kinematics, none of the strategies completely restored the shoulder girdle to its preinjured state.
Humerothoracic movements after Rockwood V lesions are best restored using the CC reconstruction technique, and scapulothoracic movements are best restored using the AC ligament reconstruction technique.
Despite the evolution of acromioclavicular joint surgery to a more anatomic coracoclavicular (CC) ligament reconstruction, no definitive guidance regarding the number and position of bone tunnels in the clavicle, as well as the ideal graft choice, is established.
The purpose of this study was to biomechanically compare the reconstruction of the CC ligament complex between gracilis- and semitendinosus-tendon grafts in 1- and 2-tunnel techniques. It was hypothesized that the gracilis tendon graft will provide comparable primary stability in both tunnel techniques while utilizing a smaller tunnel diameter.
Controlled laboratory study.
A total of 24 cadaveric shoulders (13 men, 11 women; 66 ± 7.5 years) were randomly allocated to 4 repair groups: gracilis with 1 tunnel (GT-1), gracilis with 2 tunnels (GT-2), semitendinosus with 1 tunnel (ST-1), and semitendinosus with 2 tunnels (ST-2). First, specimens were tested for native anterior, posterior, and superior translations. Then, specimens were randomly assigned to 1 of the 4 CC reconstruction groups before undergoing the same testing, followed by cyclic loading and load to failure (LTF).
The GT-2 reconstruction demonstrated significantly less translation when compared with ST-2 in anterior (
Gracilis tendon grafts using a 1- or 2-tunnel technique for CC ligament reconstruction provided comparable translation, displacement, and LTF as corresponding semitendinosus grafts. Therefore, the gracilis tendon should be considered as a biomechanical equivalent graft choice for the reconstruction of the CC ligament complex.
In a cadaveric model, the gracilis tendon demonstrated adequate fixation with minimal translation in CC ligament reconstruction while utilizing smaller diameter bone tunnels, which may help minimize the risk of complications such as loss of reduction and fracture.
There remains room for improvement in surgical outcomes after medial ulnar collateral ligament reconstruction (MUCLR) in professional pitchers. The role and influence of postoperative rehabilitation on the outcomes of MUCLR are unknown. There is a paucity of clinical data in the current literature comparing the success of various postsurgical rehabilitation protocols after MUCLR.
To summarize the current rehabilitation process for professional pitchers recovering from MUCLR, evaluates what player and surgical factors correlate with outcomes, and determines whether rehabilitation timing and milestones correlate with successful outcomes.
Case series; Level of evidence, 4.
717 professional baseball pitchers who underwent MUCLR between 2010 and 2016 were identified and included in the analysis. Player characteristics evaluated included age at the time of surgery, throwing side dominance, primary pitching role (starter vs reliever), and level of play (MLB, AAA, AA, A). Surgical factors studied included date of surgery, graft type (palmaris longus autograft vs gracilis autograft), and surgical technique (figure of 8 vs docking vs other). The rehabilitation and throwing progression details were as follows: initiation date; first throw date; dates to start throwing from various distances; longest distance thrown; first flat ground throw date; first mound throw date; and first live batting practice (BP) date. The primary outcomes of interest were the ability to return to play at any level (RTP), the ability to return to the same level (RSL), and the time to RTP/RSL.
On average, pitchers threw a baseball for the first time 4.9 months after surgery, with a broad range (2.8-14.9 months). For the 675 (94%) pitchers who were able to progress to mound throwing, the first throws off a mound occurred at a mean of 9.4 months after surgery. Before progressing to the mound, the mean longest long-toss distance reached was 137.5 feet, with a broad range (105-300 feet). A high variation in the time to RTP (7.6-53.9 months) and RSL (8.6-60.7 months) was noted. A total of 599 (84%) pitchers were able to RTP at a mean time of 14.9 ± 4.9 months after surgery (range, 7.6-53.9 months). Also, 528 (74%) pitchers were able to RSL after MUCLR at a mean of 17.4 ± 7 months (range, 8.6-60.7 months) postoperatively. Age was the most significant predictor of RTP (hazard ratio [HR], 1.03 [95% CI, 1.01-1.05];
Significant variability in the postoperative rehabilitation protocols after MUCLR was observed in 717 professional baseball pitchers. The timing of achievement of throwing progression and rehabilitation milestones postoperatively varied widely but did not correlate with outcomes. Player characteristics—except for player age and professional pitching level—did not correlate with RTP and RSL outcomes. Older pitchers and MLB pitchers were more likely to RTP, but younger players were more likely to RSL. Surgical factors did not correlate with rehabilitation outcomes.
Posttraumatic inflammation after joint injury, ranging from sprains to articular fracture, contributes to the development of arthritis, and the administration of interleukin 1 (IL-1) receptor antagonist (IL-1Ra) is a potential intervention to mitigate this response. Although IL-1Ra mitigates cartilage degenerative changes induced by IL-1, lidocaine is used for local pain management in acute joint injury. Intra-articular delivery of both drugs in combination would be a novel and possibly disease–modifying treatment. However, it is not known whether the interaction with lidocaine at clinical concentrations (1%) would alter the efficacy of IL-1Ra to protect cartilage from the catabolic effects of IL-1.
Treatment of articular cartilage with IL-1Ra in combination with a clinically relevant concentration of lidocaine (1%) will inhibit the catabolic effects of IL-1α in a manner similar to treatment with IL-1Ra alone.
Controlled laboratory study.
Fresh porcine cartilage explants were harvested, challenged with IL-1α, and incubated for 72 hours with IL-1Ra or a combination of IL-1Ra and lidocaine. The primary outcome was total sulfated glycosaminoglycan (sGAG) release. Additional experiments assessed the effect of storage temperature and premixing of IL-1Ra and lidocaine on sGAG release. All explants were histologically assessed for cartilage degradation using a modified Mankin grading scale.
The combination of IL-1Ra and lidocaine, premixed at various time points and stored at room temperature or 4°C, was as effective as IL-1Ra alone at inhibiting IL-1α–mediated sGAG release. Mankin histopathology scores supported these findings.
Our hypothesis was supported, and results indicated that the combination of IL-1Ra and lidocaine was as efficacious as IL-1Ra treatment alone in acutely mitigating biological cartilage injury due to IL-1α in an explant model.
The combination of IL-1Ra and lidocaine is stable when reagents are stored in advance of administration at varying temperatures, providing clinically relevant information about storage of medications. The ability to premix and store this drug combination for intra–articular delivery may provide a novel treatment after joint injury to provide pain relief and block inflammation–induced catabolism of joint tissues.
In hip arthroscopic surgery, capsulotomy is performed to improve visualization and allow instrumentation of the joint. Traditionally, the defect has been left unrepaired; however, increasing evidence suggests that this may contribute to persistent pain and iatrogenic capsular instability. Nevertheless, the clinical benefit of performing routine capsular repair remains controversial.
We conducted a systematic review and meta-analysis to investigate the effects of routine capsular closure on patient-reported outcomes (PROs), hypothesizing that superior PROs would be observed with routine capsular closure.
Meta-analysis and systematic review; Level of evidence, 4.
A systematic review and meta-analysis was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The terms “hip,”“arthroscopy,”“capsule,”“capsular,”“repair,” and “closure” were used to query Ovid MEDLINE, Embase, CENTRAL (Cochrane Central Register of Controlled Trials), CINAHL (Cumulative Index to Nursing and Allied Health Literature), SPORTDiscus, and PubMed. Articles with PROs stratified by capsular management were included. Multivariate mixed-effects metaregression models were implemented with study-level random-effects and fixed-effects moderators for capsular closure versus no repair and after controlling for surgical indication and preoperative PROs. The effect of repair on both the postoperative score and the change in scores was evaluated via the Harris Hip Score (HHS)/modified HHS (mHHS), Hip Outcome Score (HOS)–Activities of Daily Living (ADL), and HOS–Sport Specific Subscale (SSS), with a supplemental analysis of additional outcomes.
Of 432 initial articles, 36 were eligible for analysis, with results for 5132 hip arthroscopic procedures. The capsule was repaired in 3427 arthroscopic procedures and unrepaired in 1705. Capsular repair was associated with significantly higher postoperative HHS/mHHS (2.011; SE, 0.743 [95% CI, 0.554-3.467];
This meta-analysis is the largest to date evaluating the effect of capsular closure on PROs and demonstrates significantly higher mean postoperative scores and significantly superior improvement with repair, while controlling for the effects of preoperative score and surgical indication. The true magnitude of the benefit of capsular repair may be clarified by large prospective randomized studies using PRO measures specifically targeted and validated for hip arthroscopic surgery/preservation.
Previous meta-analyses have demonstrated superior outcomes in patients undergoing arthroscopic repair of medial meniscus posterior root tears (MMPRTs) compared with meniscectomy. However, these analyses have considered only short- or midterm outcomes and low-quality evidence.
To compare the mid- to long-term rates of radiographic osteoarthritis (OA) between repair and meniscectomy for MMPRT.
Systematic review and meta-analysis; Level of evidence, 4.
PubMed, EMBASE, Ovid/MEDLINE, and Cochrane Central Register of Controlled Trials databases were queried for articles evaluating repair and meniscectomy for MMPRT. Articles were eligible if they had a minimum mean 4-year follow-up for radiographic OA or conversion to total knee arthroplasty (TKA) and were at least level 3 evidence. Radiographic OA was assessed using Kellgren-Lawrence (KL) progression. Rates of conversion to TKA and International Knee Documentation Committee (IKDC) scores were also extracted. DerSimonian-Laird binary random-effects models were created to evaluate differences in radiographic OA and TKA conversion rates, with odds ratios (ORs) representing pooled estimates. Continuous random-effects models with standardized mean differences (SMDs) were used to compare postoperative IKDC scores.
Repair and meniscectomy cohorts were followed for a mean of 64.8 months and 62.5 months, respectively, for KL progression; and 82.8 months and 73.8 months, respectively, for TKA rates and IKDC scores. Overall, 59 of 144 (41%) patients undergoing surgical intervention for MMPRT demonstrated OA progression; 18 of 82 (22%) who underwent repair for MMPRT exhibited OA progression compared with 41 of 62 (66%) who underwent meniscectomy (OR, 0.17; 95% CI, 0.03-0.83;
Medial meniscus posterior root repair results in significantly lower rates of radiographic OA progression and conversion to TKA at >60-month follow-up. On the basis of these findings, we recommend consideration of repair of MMPRTs when degenerative changes are not severe, as it can yield improved outcomes.
Latissimus dorsi transfer (LDT) and pectoralis major transfer (PMT) were developed to treat an irreparable subscapularis tendon tear (ISScT); however, the difference in their outcomes remains unclear.
To systematically review and compare the outcomes of LDT and PMT for ISScT.
Systematic review; Level of evidence, 4.
A systematic review was performed through a comprehensive search of Embase, PubMed, and the Cochrane Library. Studies of LDT or PMT were included according to the inclusion and exclusion criteria. The primary outcome was the Constant-Murley score (CMS) at the final follow-up. Secondary outcomes included the subjective shoulder value (SSV), visual analog scale (VAS) score for pain, active shoulder range of motion, and the belly-press and lift-off tests. Postoperative failure and complication rates were the safety outcome measures. Outcomes were summarized into the LDT and PMT groups, and results were compared statistically (
Twelve studies were included in this review: 184 shoulders from 9 studies for the PMT group and 85 shoulders from 3 studies for the LDT group. For the PMT and LDT groups, the mean ages were 58.9 and 55.1 years, respectively, and the mean follow-up was 66.9 and 17.4 months, respectively. Overall, the LDT and PMT groups improved in the primary outcome (CMS) and secondary outcomes (SSV, VAS, ROM, and belly-press and lift-off tests), with low rates of failure and complication. When compared with the PMT group, the LDT group showed more significant improvements in CMS (35.2 vs 24.7;
In general, LDT showed significantly better clinical outcomes postoperatively than did PMT. The available fair-quality evidence suggested that LDT might be a better choice for ISScT. Further evaluations on the relative benefits of the 2 surgical approaches are required, with more high-quality randomized controlled studies.
Patella alta is a known risk factor for patellar instability and, in the setting of recurrent patellar instability with significant patella alta, correction of patellar height with a tibial tubercle osteotomy (TTO) may help decrease the failure of soft tissue–based stabilization.
To perform a systematic review and meta-analysis of radiographic and clinical outcomes after TTO for patella alta.
Systematic review and meta-analysis; Level of evidence, 4.
PubMed, OVID/Medline, and Cochrane databases were queried in June 2020 for studies reporting outcomes of TTO for patella alta. Data pertaining to study characteristics and design, radiographic and clinical outcome values, and incidence of complications and reoperations were extracted. DerSimonian-Laird continuous and binary random-effects models were constructed to (1) perform subgroup-based analysis of mean changes in radiographic indices after TTO and (2) quantify the pooled incidence of complications and reoperations.
Eight studies including 340 patients (420 knees) with a mean age of 24.7 ± 8.4 years were included. The mean follow-up was 53.1 months (range, 3-120 months), with 1 study reporting a mean follow-up of less than 2 years. The pooled mean anterior transfer was 5.6 mm; the mean medial transfer was 8.7 ± 1.3 mm; and the pooled mean distalization of the tibial tubercle was 12.2 ± 4.5 mm. Continuous random-effects meta-analysis determined that significant reductions in the mean Insall-Salvati ratio (1.40 vs 0.98,
TTO for patellar instability in the setting of patella alta results in a significant decrease in patellar height with varying degrees of medialization depending on the utilized technique. A mean postoperative complication rate of 7.6% was reported with a reoperation incidence of 14.3%, related primarily to hardware removal.
