Patellar fractures account for approximately 1% of all fractures. Open reduction and internal fixation is recommended to restore extensor continuity and articular congruity. However, complications such as nonunion and symptomatic hardware, still exist. Furthermore, there is a risk of re-fracturing of the healed bone during the removal of the implants. Magnesium (Mg), a biodegradable metal, has elastic moduli and compressive yield strength that are comparable to those of natural bone. Our previous study showed that released Mg ions enhanced fracture healing. However, Mg-based implants degrade rapidly after implantation and lead to insufficient mechanical strength to support the fracture. Microarc oxidation (MAO) is a metal surface coating that reduces corrosion. We hypothesized that Mg pins, with or without MAO, would enhance fracture healing radiologically, mechanically, and histologically, while MAO would decrease degradation of Mg pins.

Patellar fracture was performed on forty-eight 18-week-old female New Zealand White rabbits according to established protocol. Briefly, the patella is osteotomized transversely and a tunnel (1.1mm) was drilled longitudinally through the two bone fragments. A pin (1 mm, stainless steel, Mg, or MAO-Mg) was inserted into the tunnel. The reduced construct was stabilized with a figure-of-eight band wire (⊘ 0.6 mm stainless steel wire). Cast immobilization was applied for 6 weeks. The rabbits were euthanized at week 8 and 12 post-operation. Microarchitecture and mechanical properties of the repaired patella were analyzed with microCT and tensile testing respectively. Histological sections of the repaired patella were stained. To evaluate the effect of the MAO treatment on degradation rate of Mg pin, the volume of the Mg pins in the patella was measured with microCT.

At week 8, both Mg and Mg-MAO showed higher ratio of bone volume to tissue volume (BV/TV) than the control while there was no significant different between Mg and Mg-MAO. At week 12, Control, Mg, and Mg-MAO groups showed enlarged patella when compared to the normal patella. Tissue volume (TV) and bone volume (BV) of the patella in Mg and Mg-MAO were larger than those in the Control group. However, the Control had higher ratio of bone volume to tissue volume (BV/TV), TV density, and BV density than Mg and Mg-MAO. Tensile testing showed that the mechanical properties of the repaired patella (failure load, stiffness, ultimate strength, and energy-to-failure) of Mg and Mg-MAO were higher than that of the control at both week 8 and week 12. Histological analysis showed that there was significant new bone formation in the Mg and Mg-MAO group compared with the Control group at week 8 and 12. The degradation rate of the MAO-coated Mg pins was significantly slower than those without MAO at week 8 but no significant difference was detected at week 12.

Mechanical, microarchitectural, and histological assessments showed that Mg pins, with or without MAO, enhanced fracture healing of the repaired patella compared to the Control. MAO treatment enhanced the corrosion resistance of the Mg pins at the early time point.

Introduction

Both cross and lateral pinning are common techniques used for displaced supracondylar elbow fractures in children. Our study aims to determine whether there are any radiological differences in outcome between the two techniques. Most recent studies involving radiological evaluation of supracondylar fractures had concentrated on use of Bauman's angle or humerocapitellar angles. Rotational displacement, which has been shown to be critical for stability, is often not adequately addressed. Our evaluation measures both linear displacement using Bauman's angle and rotational displacement through the measurement of the lateral rotational percentage (LRP).

Introduction and Aims: Problem: Patellar resurfacing in TKA remains controversial. Purpose: To evaluate the results of resurfacing/non-resurfacing of the patella in a randomised controlled clinical trial at a minimum of 10 years of follow-up.

Method: One hundred knees (90 patients) with osteoarthritis were enrolled in a prospective randomised controlled double-blinded trial using the same posterior cruciate retaining total knee replacement. Patients were randomised to resurfacing or non-resurfacing of the patella. Evaluations were performed pre-operatively and yearly to a minimum of 10 years (range 10.1–11.5 years) postoperatively. Disease-specific (Knee Society Clinical Rating System), functional (stair climbing, knee flexion/extension torques, patellar examination) outcomes were measured. Patient satisfaction, anterior knee pain, and patellofemoral questionnaires were completed. Intra-operative grading of the articular cartilage was performed.

Results: No patients were lost to follow-up; 46 knees remained alive. Nine revisions (9/90–10%) were performed – 7/48 (15%) in the non-resurfaced and 2/42 (5%) in the resurfaced group. Three knees in the non-resurfaced group were revised to a resurfaced patella for anterior knee pain. One resurfaced patella was complicated by AVN and fracture, requiring revision. No significant difference was found between the groups regarding revision rates, KSCR score, functional, satisfaction, anterior knee pain, patellofemoral, and radiographic outcomes. Intraoperative cartilage quality was not a predictor of outcome.

Conclusions: This study represents the longest follow-up to date of a randomised controlled clinical trial to examine patellar resurfacing in TKA. The results showed no significant difference between the groups for all outcome measures at a minimum of 10 years.

Introduction: A retrospective study of the clinical and radiographic results of the Mallory-Head total hip arthroplasty was conducted.

Materials and Methods: Sixty-seven patients (76 hips) with a mean age of 50 years who had Mallory-Head total hip arthroplasty were studied. The mean follow-up period was 10.1 years (9–13years).

Results: Excellent or good clinical results were found in 64 patients. Minimal thigh pain was found in 3 patients (4.4%). Seventy-one hips (93.4%) showed fixation by bony ingrowth and three (3.9%) showed the stable fibrous fixation. Bony on and ingrowth was also observed in 16 hips (21%) at distal smooth and of the grit-blast area. Two femoral components were revised: one for subsidence, and the other for the recurred infection. Therefore, the success rate was 97.3%.

Conclusion: The authors believe that these good results are a consequence of excellent bony ingrowth on the proximal two-thirds of the femoral surface area. In conclusion, proximal plasma-spray coating and tapered shape of the Ti-stem showed excellent bony ingrowth and initial stability. Our results indicate that distal tapered shape may be an important element in the design of cementless stems.

Congenital pseudarthrosis of the lower limb is not uncommon, with an incidence of approximately 1 in 150,000.

In contrast, isolated congenital pseudarthrosis of the fibula without tibial involvement is a very rare. There were only 11 cases of true isolated congenital pseudarthrosis of the fibula described in the English literature till 1999. We describe 3 patients diagnosed and treated in our institution. The current management is also discussed, highlighting the unique treatment options in this rare condition.