Journal of Orthopaedic Surgery

To investigate the nerve endings of the adult temporomandibular joint disk, in particular the presence and configuration of the sensory nerve endings by silver staining and electron microscopy.

20 cadaveric temporomandibular joints impregnated with silver stain were studied using an optical microscope; 2 other joints were studied using a transmission electron microscope.

Free nerve endings were found in the disk parenchyma of all joints. Golgi-Mazzoni corpuscles, Ruffini corpuscles, and articular corpuscles were also observed as sensory nerve end organs. Myelinated and nonmyelinated nerve fibres were visualised in the disk parenchyma using the transmission electron microscope.

Free nerve endings and sensory nerve end organs are present in the disk parenchyma of the human temporomandibular joint and are associated with sensation and proprioception, just as they are in the acetabular labrum, glenoid labrum, triangular fibrocartilage complex, and meniscus.

To study the prevalence of osteoarthritis, osteoporotic vertebral fractures, and spondylolisthesis among elderly residents of a Japanese village and to examine the correlation between radiographic evidence of abnormality and lower back pain.

205 men (mean age, 70.7 years) and 323 women (mean age, 70.5 years) in a Japanese village participated in this cross-sectional study. Plain lateral radiographs were taken from the lower thoracic spine to the sacral spine. They were evaluated by 3 independent orthopaedic surgeons for degree of osteoarthritis (using Weiner grading system) and the presence of osteoporotic vertebral fractures and spondylolisthesis.

The prevalence of osteoarthritis in elderly Japanese villagers was 38.3%, whereas that of osteoporotic vertebral fractures and spondylolisthesis was 17.8% and 8.9%, respectively. There was no significant difference in osteoarthritis between men and women, but osteoporotic vertebral fractures and spondylolisthesis were significantly more common in females (p<0.01). No significant correlation was observed between lower back pain and radiographic evidence of degenerative spinal disease.

The prevalence of spondylolisthesis in elderly Japanese was much lower than that in whites or African Americans. The prevalence of osteoarthritis or osteoporotic vertebral fractures was comparable with other English or US studies. Radiographic evidence of osteoarthritis, osteoporotic vertebral fractures, and spondylolisthesis is not necessarily associated with lower back pain.

To assess the prevalence of proximal high-origin anterior tibial artery and its surgical significance.

100 knees were prospectively studied using colour Doppler ultrasonography. No patient had a history of lower-limb arterial pathology or previous knee surgery. All ultrasound images were assessed by a single experienced vascular technician to eliminate inter-observer variability.

The mean age of the patients was 56 years (range, 21–96 years). Prevalence of the high-origin anterior tibial arterial pattern was 6%, greater than that reported by previous angiographic or cadaveric studies. In all patients with high-origin anterior tibial artery, the artery was in direct contact with the posterior cortex of the tibia.

This highlights the danger of using sharp instruments in knee procedures that involve extension of osteotomy to the posterior tibial cortex, particularly high-tibial osteotomy and total knee replacement. Knowledge of the anatomical variations in the branching of the popliteal artery is important because damage to its branches can be limb- or life-threatening.

To compare the status of bony union seen on plain radiography versus computed tomography (CT) following tension band repair for refractory spondylolysis.

14 patients (12 men and 2 women; mean age, 23 years; age range, 16–56 years) with a mean follow-up period of 6.35 years were included. All patients were operated on by one senior surgeon using either a Scott procedure (n=2) or van Dam modification of the Scott procedure (n=12). Bony union of the pars was assessed using both plain radiography (anteroposterior, lateral, and oblique views) and reverse gantry CT. The presence of bony union was determined if a bridging bone was shown in the images. The Oswestry Disability Index was measured at 6-year follow-up.

13 (93%) of 14 patients showed bony union on plain/oblique radiographs versus 7 (50%) on CT scan. The mean Oswestry Disability Index was 28 (good to excellent). The high incidence of nonunion shown on CT scanning did not correlate well with clinical results.

Bony nonunion is more difficult to visualise on plain radiographs than reverse gantry CT. CT demonstrates more clearly the presence or absence of the bridging bone. Clinical results do not correlate with bony union, indicating that bony union is not required to achieve good results.

To compare 2 methods of fusion in the treatment of lumbar spondylolisthesis: posterior lumbar interbody fusion (PLIF) and intertransverse fusion (ITF).

20 patients with lumbar spondylolisthesis were randomly allocated to one of 2 groups: decompression, posterior instrumentation, and PLIF (n=10) or decompression, posterior instrumentation, and ITF (n=10). The Oswestry low back pain disability questionnaire was used for clinical assessment. Radiography was performed preoperatively and postoperatively to assess the reduction of spondylolisthesis or slip.

In the PLIF and ITF groups, 87.5% and 100% had a satisfactory clinical result, and 48% and 39% had reduced spondylolisthesis, respectively. Both had a fusion rate of 100%. PLIF showed better reduction of spondylolisthesis, although ITF achieved a better subjective and clinical outcome.

Morbidity and complications are much higher following PLIF than ITF. ITF is recommended because of the simplicity of the procedure, lower complication rate, and good clinical and radiological results.

To assess and evaluate the usefulness of 7 morphological measurements of the acetabulum in establishing the prevalence of acetabular dysplasia in the Singaporean population.

Standardised plain anteroposterior radiographs of 522 hip joints of 261 asymptomatic patients (mean age, 60 years; range, 16–99 years) were evaluated. The 7 morphological measurements were centre-edge angle, acetabular angle, depth-to-width ratio, roof obliquity, extrusion index, lateral subluxation, and peak-to-edge distance.

19 (7.3%) patients were acetabular dysplastic (centre-edge angle of <20 degrees). The mean centre-edge angle was 31.2 degrees (range, 5–52 degrees), acetabular angle 39.46 degrees (range, 10–58 degrees), depth-to-width ratio 0.32, roof obliquity 7.86 degrees, extrusion index 0.18, lateral subluxation 9.9 mm, and the peak-to-edge distance 15.65 mm.

Centre-edge angle was the most useful measurement and correlated significantly with acetabular angle, extrusion index, peak-to-edge distance, and roof obliquity. These preliminary results show a relatively higher rate (7.3%) of acetabular dysplasia in the Singaporean population, compared with other similar but larger Asian studies performed in Hong Kong (1.1%) and Korea (1.8%).

To evaluate the clinical, radiological, and densitometric changes in the bone-remodelling patterns of femoral stems aligned in neutral, valgus, or varus positions.

Between February and October 2000, 70 patients underwent unilateral total hip arthroplasty for primary osteoarthritis using an uncemented Anatomique Benoist Girard (ABG) II stem. 69 patients (30 males and 39 females) with a mean age of 59 years (range, 38–76 years) and a mean body weight of 79.3 kg (range, 29–110 kg) completed 3 years' follow-up on bone remodelling. The clinical, radiological, and densitometric changes of the neutral, valgus, and varus groups were evaluated, and the difference in bone-remodelling patterns between the 3 groups was analysed.

54 patients had neutrally placed stems, while varus and valgus malalignment occurred in 6 and 9 patients, respectively. Clinical and radiological evaluations were very similar among the 3 groups. Only densitometry could detect traceable changes resulting from the differing biomechanics of the neutral, varus, and valgus stem alignments.

The ABG II stem design made moderate errors in alignment biomechanically tolerable. Alignment defects had no clinical consequences and resulted in minimal differences in bone remodelling.

To compare the pharmacokinetic profile of tobramycin in blood, urine, and at the operative site following the use of Simplex-tobramycin bone cement in primary total hip replacement between patients with and without renal dysfunction.

Six patients with renal dysfunction underwent cemented primary total hip replacement for osteoarthritis. The elution characteristics of Simplex-tobramycin bone cement in the 6 patients with renal dysfunction were compared with 9 patients who had normal renal function. Blood, urine, and drainage fluid specimens were collected for 72 hours postoperatively.

Very high concentrations of tobramycin were seen in the drainage fluid of the 2 groups. Mean serum tobramycin levels peaked at postoperative 3 hours, and declined rapidly to negligible levels at 72 hours in both groups. Mean urinary tobramycin concentrations peaked at postoperative 12 hours and declined rapidly until 48 hours in both groups. Urinary tobramycin was excreted significantly more slowly in renal dysfunction group in the first 12 hours, but not thereafter. Although serum creatinine levels of the renal dysfunction group were higher throughout the study period, the difference was not significant. Both groups achieved excellent local delivery of the antibiotic with minimal systemic concentrations.

Simplex-tobramycin bone cement appears to be an effective and safe means to deliver antibiotic for patients with renal dysfunction who undergo total hip replacement.

To evaluate the short-term clinical and functional outcomes of total hip arthroplasty performed for physiologically active elderly patients with Garden type-3 or -4 femoral neck fracture.

Records of 47 consecutive patients (40 female, 7 male) with type-3 or -4 femoral neck fracture (Garden classification) who underwent cemented total hip arthroplasty at our hospital during January 1999 to December 2002 were reviewed. Radiological and clinical (Harris functional hip score and Oxford hip score) assessments of 38 patients were measured with a mean follow-up period of 21 months (range, 4–48 months).

The mean age of the 47 patients was 75 years (range, 62–89 years). Records of 9 patients were excluded because of death, lost to follow-up, and development of deep infection that necessitated implant removal and excision arthroplasty. The mean Harris hip score of the 38 patients was 83 (range, 59–97), whereas the mean Oxford hip score was 25.2 (range, 14–33). Pain in the hips was absent in 30 patients, 6 had slight pain occasionally, and 2 patients had mild-to-moderate hip discomfort. No signs of aseptic loosening or change in implant position were noted on radiographic assessment. Two cases of dislocation were reduced by closed reduction. Two patients had deep wound infection and were treated with debridement, implant removal, and conversion to girdle stone.

This short-term study showed that total hip arthroplasty for femoral neck fracture had good postoperative results in functional hip and pain scores. More attention should be paid to coexisting medical illness (e.g. diabetes mellitus, hypertension, and ischaemic heart disease) and prevention of infection.

To assess early postoperative rehabilitation outcome following computer-assisted total knee arthroplasty (TKA) or standard instrumentation TKA using a medial parapatellar or subvastus approach.

A prospective controlled trial of 70 consecutive patients undergoing TKA with a low contact stress rotating platform prosthesis was conducted. Patients were randomised to receive surgery with either computer navigation or standard instrumentation. A medial parapatellar or subvastus approach was used according to the surgeons' preference. Outcome measures included preoperative knee function, intra-operative factors, and postoperative rehabilitation.

Duration of surgery was significantly longer when using computer navigation; however, operating time decreased with greater experience. A higher incidence and duration of early postoperative quadriceps dysfunction was associated with computer-assisted TKA through the medial parapatellar approach than through the subvastus approach or TKA performed with standard instrumentation. No patient who received surgery through the subvastus approach had a lag of more than 20 degrees, at 48 hours postoperatively, regardless of the instrumentation used.

Computer-assisted TKA through a medial parapatellar approach was associated with delayed recovery of the quadriceps during early postoperative rehabilitation. This was due to the additional quadriceps dissection required to place the femoral tracking array. The subvastus approach is therefore recommended for computer-assisted TKA.

To assess the efficacy of our protocol for treatment of displaced Gartland type-3 supracondylar fractures of the humerus in children.

Records of 43 children with displaced Gartland type-3 supracondylar fractures of the humerus admitted from October 1997 to October 2003 were reviewed. Patients were treated within 12 hours of admission by closed reduction (n=33) or open reduction (n=10). Crossed medial and lateral Kirschner wires through a medial approach were used in all patients. A 3-cm incision was made medially to identify the correct entry point of the medial wire, and thus prevent ulnar nerve injury. The incision was extendable for open reduction if closed reduction was unsuccessful.

The mean age of the 43 patients was 7.2 years (range, 2–14 years). The mean follow-up period was 48 months (range, 12–84 months). 83% of the fractures occurred in boys. All fractures were closed, extension type, with 28 (65.1%) involved the right elbow. No patient had iatrogenic ulnar nerve injury. All patients showed satisfactory results according to Flynn criteria.

If closed reduction is unsuccessful, open reduction and open medial placement of crossed Kirschner wires can provide reliable results. The small medial incision provides a viewing point for entry of the wire and prevents iatrogenic injury of the ulnar nerve. It is cosmetically more acceptable and can be extended to facilitate open reduction.

To review the subjective and functional results of basal thumb metacarpal osteotomy for the treatment of trapeziometacarpal osteoarthritis.

Between July 1993 and November 1998, 35 thumb osteotomies without internal fixation were performed on 33 patients in the Christchurch Hospital, New Zealand. Records of 28 thumbs (13 right and 15 left) of 26 patients (17 women and 9 men) were available for review. Patients were reviewed using strength testing and the Michigan Hand Outcomes Questionnaire.

The mean age of the 26 patients was 54 years (range, 30–69 years). Of the 28 thumbs, 22 (21 patients) had good or excellent results, 2 fair, one poor. The remaining 3 thumbs (3 patients) required further revision and were classified as failures. The mean follow-up period of the 25 thumbs (24 patients) not requiring revision was 34 months (range, 12–73 months). Good thumb motion was present in all hands with no trapeziometacarpal instability seen. Compared with the normative data, the strengths of key pinch, pulp pinch, and tripod pinch of our patients were significantly lower (22–32% lower), but not the grip strength. Michigan Hand Outcomes Questionnaire scores increased 28 (range, 1–56) points after surgery, with significant improvement especially in pain (+44 points), activities of daily living (one-handed tasks, +41 points), and satisfaction (+35 points).

Basal thumb metacarpal osteotomy is a straightforward, conservative procedure that should be considered for grades II and III trapeziometacarpal osteoarthritis.