Anterior cruciate ligament tear in Hong Kong Chinese patients

OBJECTIVE

To investigate the associations between patient sex, age, cause of injury, and frequency of meniscus and articular cartilage lesions seen at the time of the anterior cruciate ligament reconstruction.

SETTING

University affiliated hospital, Hong Kong.

PATIENTS

Medical notes and operating records of 672 Chinese patients who had received anterior cruciate ligament reconstruction between January 1997 and December 2010 were reviewed. Data concerning all knee cartilage and meniscus injuries documented at the time of surgery were analysed.

RESULTS

Of the 593 patients, meniscus injuries were identified in 315 (53.1%). Patients older than 30 years were more likely to suffer from meniscal injury compared with those younger than 30 years (60% vs 51%, P=0.043). Longer surgical delay was observed in patients with meniscal lesions compared with those without (median, 12.3 months vs 9.1 months, P=0.021). Overall, 139 cartilage lesions were identified in 109 (18.4%) patients. Patients with cartilage lesions were significantly older than those without the lesions (mean, 27.6 years vs 25.1 years, P=0.034). Male patients were more likely to have chondral injuries than female patients (20.1% vs 10.9%, P=0.028). The risk of cartilage lesions was increased by nearly 3 times in the presence of meniscal tear (P<0.0001; odds ratio=2.7; 95% confidence interval, 1.7-4.2).

CONCLUSIONS

Increased age and surgical delay increased the risk of meniscal tears in patients with anterior cruciate ligament tear. Increased age, male sex, and presence of meniscal tear were associated with an increased frequency of articular lesions after an anterior cruciate ligament tear.

Femoral radiographic landmarks for popliteus tendon reconstruction and repair: a new method of reference

BACKGROUND

Although the popliteus muscle-tendon complex is one of the most important structures in controlling posterolateral rotatory stability of the knee, not much literature has been reported concerning the use of femoral radiographic landmarks of the popliteus tendon in repair and reconstruction.

HYPOTHESIS

By using standardized radiographic techniques, the femoral insertion of the popliteus tendon could be more precisely determined by the Blumensaat line than by the extension line of the posterior cortex.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Ten fresh-frozen human knees were dissected, and the popliteus tendon was exposed. After identification of the femoral insertion site of the popliteus tendon, the insertion's center was indicated with a radiographic marker. True lateral radiographs of the distal femur were taken, and the digital radiographic images were analyzed by 2 independent observers.

RESULTS

The femoral insertion site of the popliteus tendon was found to be a mean 47.5% ± 5.2% across the width of the femoral condyle, 60.7% ± 7.8% along the perpendicular bisector of the Blumensaat line, 0.3 ± 1.7 mm posterior to the extension line of the posterior femoral cortex, and 20.5 ± 3.8 mm distal to the perpendicular line at the Blumensaat point. The variance from the mean point by using the Blumensaat line as a reference was significantly smaller than by using the extension line of the posterior cortex (mean, 2.6 vs 3.6 mm; P = .044).

CONCLUSION

A reproducible anatomic and radiographic reference point for the femoral insertion of the popliteus tendon can be determined using standardized radiographic techniques and can be more precisely determined by the Blumensaat line compared with the extension line of the posterior femoral cortex.

CLINICAL RELEVANCE

This radiographic information provides an adjunctive tool for preoperative, intraoperative, and postoperative assessments of surgical repair and reconstruction of the popliteus tendon.

Tunnel positions in transportal versus transtibial anterior cruciate ligament reconstruction: a case-control magnetic resonance imaging study

PURPOSE

The purpose of this study was to examine the difference in the position of bone tunnels prepared by the transportal technique versus the transtibial technique in anterior cruciate ligament (ACL) reconstruction.

METHODS

A consecutive series of 42 patients receiving single-bundle ACL reconstructions were recruited between July 1, 2007, and December 31, 2008. The preparations of the femoral tunnel were performed by the transtibial technique in the first 21 cases and by the transportal technique in the subsequent 21 cases. Magnetic resonance imaging examination was performed in 39 patients (93%) 1 year after the index operation (20 transtibial and 19 transportal). Optimal tunnel position was defined as a lateralized femoral tunnel at a position of less than 11 o'clock for a right knee or more than 1 o'clock for a left knee, an adequate posteriorized femoral tunnel in the fourth quadrant of the modified Bernard line, and a tibial tunnel located in the second quadrant of the modified Amis line.

RESULTS

The average clock position was 10:18 in the transportal group and 10:54 in the transtibial group (P < .001). Five outliers were found in the transtibial group but none in the transportal group. Concerning the femoral tunnel position on the sagittal-cut magnetic resonance imaging scan, the average position along the modified Bernard line was 74% in the transportal group and 69% in the transtibial group (P = .029). Concerning the tibial tunnel position, the average tibial tunnel positions along the modified Amis line were 47% and 52%, respectively (P = .019).

CONCLUSIONS

The adoption of the transportal technique in single-bundle ACL reconstruction produced improved positions in both the femoral and tibial tunnels when compared with the transtibial technique.

LEVEL OF EVIDENCE

Level III, case-control study.

Distal femur rotation relates to joint obliquity in ACL-deficient Chinese

BACKGROUND

The lower limb osteometry of Chinese differs from that of whites. The joint line of the knee in the coronal plane in Chinese is more medially inclined and the posterior condylar angle of the distal femur in the axial plane is larger. However, it is unclear whether there is any direct association between the coronal plane and axial plane osteometry.

QUESTIONS/PURPOSES

We asked whether the joint line obliquity of the knee is related to the posterior condylar angle of the distal femur in young Chinese subjects.

METHODS

Ninety-nine young Chinese patients with anterior cruciate ligament injuries were recruited. The lower limb alignment and joint line obliquity were measured using standing long radiographs of the whole lower limb. The rotational alignment of the distal femur was assessed in the axial cuts of the MRI.

RESULTS

The distal femur rotational alignment was associated with the obliquity of the knee in Chinese. The posterior condylar angle was 5° ± 2°. The knee was 5° ± 3° medially inclined.

CONCLUSIONS

The joint line of the knee in a group of young Chinese patients was more medially inclined than that of whites. The posterior condylar angle of the distal femur was larger. The presence of an association between distal femur rotational alignment and joint line obliquity in this group of young Chinese patients suggests a possible developmental cause explaining the difference in osteometry between races.

Early results of all-inside meniscal repairs using a pre-loaded suture anchor

OBJECTIVES

To report the clinical and radiological results of all-inside meniscal repairs using a pre-loaded suture anchor.

DESIGN

Case series.

SETTING

Regional hospital, Hong Kong.

PATIENTS

From January 2008 to June 2010, 51 patients with a mean age of 26 (range, 15-48) years with 57 meniscal tears underwent meniscal repair utilising the all-inside meniscal repair technique entailing a pre-loaded suture anchor. All tears were located at red-red or red-white zones. Concurrent anterior cruciate ligament reconstruction was performed in 37 (73%) of the patients. Patients were evaluated postoperatively based on the International Knee Documentation Committee score, clinical examination, and magnetic resonance imaging. Presence of locking, joint-line tenderness, effusion, and positive McMurray test were considered to indicate clinical failure.

RESULTS

The mean follow-up was 19 (range, 12-39) months. An average of 2 (range, 1 to 4) suture devices was used per patient. The mean tear size was 20 (range, 10-40) mm. In all, 10 (18%) of the tears had failed clinically and 11 (19%) appeared unhealed on postoperative imaging. The mean International Knee Documentation Committee score improved significantly from 62 preoperatively to 81 postoperatively (P<0.001). Patients with concurrent anterior cruciate ligament reconstruction had better corresponding scores postoperatively than preoperatively (mean, 83 vs 65, P<0.001). The clinical and radiological outcome was not related to the chronicity, location or length of the tear, or patient age. No postoperative extra- or intra-articular complications were encountered.

CONCLUSION

All-inside meniscal repair using a pre-loaded suture anchor is safe and effective, and yielded an 83% clinical and 81% radiological success rate.

Delay in ACL reconstruction is associated with more severe and painful meniscal and chondral injuries

PURPOSE

The goal of our study was to investigate the associations between surgical delay, pain and meniscus, and articular cartilage lesions seen at the time of ACL reconstruction.

METHODS

One hundred and sixty-two consecutive patients who had received ACL reconstruction were recruited. The preoperative International Knee Documentation Committee (IKDC) questionnaires, and cartilage and meniscal lesions seen at the time of surgery were analysed.

RESULTS

Patients with surgery within 12 months were less likely to have meniscus injury (59.8/77.4 %, p = 0.032), and the meniscus injury was more likely to be salvageable. (56.3/36.0 %, p = 0.042). Patients with meniscal tear larger than 10 mm had higher pain intensity than tear <10 mm (mean 6.8/8.2, p = 0.007). Patients older than 35 years of age were more likely to suffer from cartilage injury (76.4/39.1 %, p = 0.004). Patients with cartilage lesions had longer surgical delay (mean 18.9/12.1 months, p = 0.033). The presence of meniscal tear increased the risk of cartilage lesions (p = 0.038, OR = 2.14). Patients with cartilage lesions had a greater pain frequency (mean 6.9/7.7, p = 0.048). Moderate correlation was found between the size of cartilage lesion and the frequency of pain (p = 0.013).

CONCLUSIONS

Increased surgical delay was associated with an increased incidence of meniscus and articular cartilage injuries in patients suffering from ACL tear; also, the meniscus was less likely to be salvageable. The presence of cartilage lesions was associated with an increased frequency of pain. Size of meniscal and cartilage lesions was significantly associated with pain.

Osteomalacia: a case series of patients with atypical clinical orthopaedic presentations

Osteomalacia is uncommon in an affluent subtropical city like Hong Kong, where sunlight exposure is adequate and nutritional support is good. We present three patients who had osteomalacia with different presentations. A 74-year-old male with oncogenic osteomalacia presented with multiple bone pain. His biochemical markers returned to normal 4 days postoperatively after resection of a second toe giant cell tumour of tendon sheath. A 62-year-old woman with a history of liver problem and proximal muscle weakness was admitted with atraumatic fracture of the left distal humerus due to osteomalacia. An 81-year-old vegetarian woman with inadequate sun exposure complained of multiple bone pains. Subsequent investigation revealed dietary- and sunlight-deficient osteomalacia with multiple bony abnormalities including marked femur bowing.