Hemiepiphysiodesis using tension band plates: does the initial screw angle influence the rate of correction?

PURPOSE: When using tension band plates for angular deformity correction, the literature is unclear regarding the most effective screw insertion angle to use. This study evaluates the correlation between initial screw angle and the average rate of correction during hemiepiphysiodesis using tension band plates. METHODS: This retrospective study includes 35 patients (47 physes) with genu valgum deformity (17 idiopathic and 18 fibular hemimelia) who underwent insertion of Eight-Plates between 2010 and 2015. Initial screw angle was determined from the intraoperative fluoroscopic images. Radiographs were obtained within three months of surgery, and follow-up films were obtained every three to six months. Change in mechanical lateral distal femoral angle, medial proximal tibial angle and screw angle was obtained from each follow-up radiograph. Initial screw angle was correlated with the average rate of correction during the entire treatment period. The average rate of angular correction during first and last follow-up periods was also compared. RESULTS: The relationship between the initial screw angle and the mean rate of angular correction was not statistically significant (p = 0.2). The rate of angular correction during the first follow-up period (mean of 4.7 months) was 0.86° per month compared with 0.71° per month during the last follow-up period (mean of 5.1 months). CONCLUSION: Application of a tension band plate with a divergence angle ranging from 0° to 30° results in similar rates of angular correction. For surgeons inserting screw-plate tension band devices, there does not seem to be any necessity to make the screws parallel or divergent. We recommend that screw placement be anatomically correct, i.e. not impinging on the physis, rather than favouring any particular divergence angle. LEVEL OF EVIDENCE: IV.

Evaluation of the external fixator TrueLok Hexapod System for tibial deformity correction in children.

BACKGROUND: Tibial deformities are common in paediatric orthopaedic practice. Correcting multiplanar tibial deformities associated with lower limb length discrepancy can be challenging. Hexapod external fixation with gradual correction has been proven effective in this situation. OBJECTIVE: To assess clinical and radiological outcomes of gradual tibial deformity correction using the external fixator TL-HEX™ (Orthofix) in children. HYPOTHESIS: TL-HEX™ is effective in correcting tibial deformities in children. PATIENTS AND METHODS: This multicentre retrospective study collected data from the medical files of 26 patients with 31 tibial deformities treated by gradual correction using TL-HEX™. The tibial deformities were due to congenital defects in 11 (35%) cases, Blount's disease in 9 (29%) cases, pseudo-achondroplasia in 4 (13%) cases, and other causes in 7 (23%) cases. Mean age at surgery was 11.9 years. In each patient, antero-posterior long leg radiographs obtained pre-operatively and at last follow-up were used to measure parameters including the mechanical axis deviation (MAD), medial proximal tibia angle (MPTA), and leg length discrepancy (LLD). RESULTS: The mean healing index was 39.3 days/cm (range, 32-58 days/cm). The overall complication rate was 61%, with 11 unplanned visits. Superficial pin tract infection was the most common complication. Significant decreases between the pre-operative and post-operative assessments occurred in mean MAD (from 32.1mm to 10.2mm, P<0.001) and mean LLD (from 36.8mm to 9.1mm, P<0.001). Patients who underwent proximal tibial osteotomy had a significant improvement in MPTA, from 80.6° to 88.5° (P=0.006). DISCUSSION: This is the first clinical study specifically designed to assess outcomes of TL-HEX™ limb lengthening and deformity correction. MAD, MPTA, and LLD were significantly improved at last follow-up. MAD was greater than 10mm at last follow-up in only 11patients. The complication rate was similar to those reported with other external fixators. TL-HEX™ is effective in the management of tibial deformities in children. LEVEL OF EVIDENCE: IV (retrospective study).

Acute knee injuries.

Skeletally immature athletes do get major knee injuries. Hemarthrosis is associated with peripheral meniscal tears, anterior cruciate ligament ruptures, tibial tubercle avulsion injuries, and patellar/femoral osteochondral fractures and cannot be ignored. The primary diagnostic tool for patients with a knee injury is a clinical examination by a physician well trained in knee evaluation. MR imaging has significant limitations in this age group. The algorithm for anterior cruciate ligament injury treatment must take into account the patient's physiologic maturity, not chronological age.

The role of low molecular weight heparin in total knee arthroplasty.

Low-molecular-weight heparin prophylaxis is an acceptable, if not superior, alternative to heparin and warfarin prophylaxis in TKA. Considering the current popularity of pharmacologic prophylaxis after total hip and total knee arthroplasty and the advantages of low-molecular-weight heparins over traditional pharmacologic agents, these agents have the potential to become the prophylactic agent of choice against DVT in TKA. There are several practical differences between low molecular weight heparins and warfarin. Low molecular weight heparins are administered by subcutaneous injection and do not require drug-level or blood monitoring. Warfarin, although administered orally, must be maintained within an appropriate international normalized ratio (INR=2-3) with daily dose adjustments and takes 36 hours to produce a measurable effect, which may leave patients relatively unprotected during the early postoperative period. Comparative trials have demonstrated that low molecular weight heparins are more efficacious than warfarin in producing a greater overall reduction in the incidence and risk of DVT, but show similar rates of PE. Some studies suggest that bleeding may be a greater problem with low molecular weight heparin. Despite the superior efficacy of low molecular weight heparin, the prevalence of venous thromboembolism after TKA continues to be substantial compared with total hip arthroplasty, with at least a quarter of patients still affected. Additional prophylaxis strategies for this indication are needed and could include combining mechanical prophylaxis (eg, external pneumatic compression) with low molecular weight heparin. An appropriate management strategy should be established for all patients undergoing TKA. This should include identification of high-risk patients, cautious transfusion of blood products, pharmacologic prophylaxis with an acceptable agent for TKA, early mobilization, postoperative screening in high-risk patients, and continuing pharmacologic prophylaxis for an appropriate period postoperatively.

The role of glenohumeral capsular ligaments in internal and external rotation of the humerus.

The purpose of this study was to define the relationship between internal and external rotation of the humerus and the lengths of the anterior and posterior components of the glenohumeral capsuloligamentous complex. Six cadaveric shoulders (with intact ligaments and humeri) were stripped of all muscles. Each shoulder was mounted in its correct anatomic position. The extent of internal and external rotation of the humerus was then measured 36 times (at 10 degrees intervals in a 360 degrees humeral cone of motion). One component of the glenohumeral capsuloligamentous complex was lengthened, and the humeral rotation was again measured 36 times. The process of lengthening was done by cutting the ligament and replacing it with a beaded chain and catches sutured across the joint. The process of lengthening each component was repeated in 12 combinations, each with a different anterior and posterior component length. Humeral rotation was measured 36 times using a specially designed goniometer. The length of the anterior component of the glenohumeral capsuloligamentous complex most affected external humeral rotation, and the length of the posterior component most affected internal humeral rotation. However, the lengths of both the anterior and posterior components shared in limiting rotation at a number of positions.