Gemella haemolysans Infection in Total Hip Arthroplasty.

Gemella haemolysans is a Gram-positive coccus and commensal of the upper respiratory tract and oral mucosa that rarely causes clinically important infections. There is only one previous report of this organism causing periprosthetic infection, in a total knee arthroplasty. We present a case of septic loosening of an uncemented total hip arthroplasty due to G. haemolysans, in an asplenic patient with insulin dependent diabetes mellitus. Treatment with two-stage revision has been successful at 7 years of follow-up.

Sciatic palsy after total hip arthroplasty associated with vascular graft occlusion.

Sciatic nerve palsy is a well-recognised complication of total hip arthroplasty, and causes include direct injury during surgery (crushing or electrocautery), compression or stretching of the nerve, thermal damage caused by leaked bone cement, trauma during dislocation or reduction of the hip, haematoma, traction caused by leg lengthening or inadvertent intraneural injection from nerve blocks. We describe what we believe to be a case of sciatic nerve ischemia due to intra-operative arterial occlusion, and we discuss the vascular anatomy which may have contributed.

The long-term benefit of computer-assisted surgical navigation in unicompartmental knee arthroplasty.

We reviewed the outcomes of 30 consecutive primary unicompartmental knee arthroplasties (UKA) performed by a single surgeon for medial compartmental osteoarthritis. Fifteen Allegretto knees were implanted without computer navigation and 15 EIUS knees were implanted with navigation. We compared the survivorship, radiological and clinical outcomes of the two groups at an average of 8.9 years and 6.9 years respectively. The patients were assessed clinically using the Oxford Knee Score (OKS) and radiologically using long-leg weightbearing films and non-weightbearing computed tomography alignment measurements. The overall survivorship was 86.7% at 9 years. A higher proportion of navigated knees were well aligned with a more reproducible position and malaligned knees tended to have a less favourable OKS. However, we found no statistically significant difference in survivorship, clinical outcome and radiological alignment between the two groups.

Hip joint range of motion restriction precedes athletic chronic groin injury.

Although a restricted hip range of motion has been previously associated with chronic groin injury the temporal course of this association remains unclear. Accordingly the purpose of this prospective cohort study was to report preliminary findings examining whether hip joint range of motion restriction is associated with subsequent onset of athletic chronic groin injury. End-range internal and external hip joint range of motion was determined in 29 elite Australian football players, without previous history of groin injury. The players were followed for two subsequent playing seasons for the development of chronic groin injury. Four athletes developed chronic groin injury defined as at least 6 weeks of groin pain and missing match playing time. In athletes that developed chronic groin injury a lower body weight (p=0.02) and reduced total hip joint range of motion (p=0.03) were found to be associated. This study suggests that hip stiffness is associated with later development of chronic groin injury and as such may be a risk factor for this condition. This work should be viewed as preliminary and caution is advised in applying the conclusion to clinical practice as the numbers in this study were small.

Magnetic resonance imaging evaluation of biodegradable transfemoral fixation used in anterior cruciate ligament reconstruction.

PURPOSE: The study was designed to evaluate bioabsorbable transfemoral fixation in anterior cruciate ligament (ACL) reconstruction using hamstring tendon as graft. Magnetic resonance imaging (MRI) was used to assess the continuity of the bioabsorbable implant at different stages of the patients' rehabilitation. TYPE OF STUDY: Retrospective case series. METHODS: Forty-nine patients underwent ACL reconstruction performed by a single surgeon. The graft, a tensioned quadrupled semitendinosus tendon, was fixed proximally using a bioabsorbable TransFix implant (Arthrex, Naples, FL). The patients underwent an accelerated rehabilitation program and were assessed clinically at regular intervals postoperatively using MRI, with specific attention focused on the implant. RESULTS: The average time from surgery to MRI was 28 weeks (range, 4 to 54 weeks). All implants were fully visible with no evidence of resorption. Five implants were fractured at an average of 20 weeks postoperatively (range, 9 to 47 weeks). Three implants showed deformation but no definite fracture at an average of 14 weeks (range, 12 to 17 weeks). This amounts to 16% of implants with fractures or deformation, many close to the period of theoretical graft incorporation. All patients were clinically stable with no symptoms or signs or instability on clinical review and all had returned to preinjury sporting activities. CONCLUSIONS: Transfemoral biodegradable implants have the potential to fracture or deform during their postoperative course in tensioned hamstring tendon ACL reconstruction. Although no apparent detrimental effect was found in our series, further research is needed on this device before it can be recommended for ACL reconstruction. We also question the idea that rigid fixation for the ACL graft for the entire healing process is required. LEVEL OF EVIDENCE: Level IV, retrospective case series.

The nonoperative management of periprosthetic fractures associated with the Birmingham hip resurfacing procedure.

We reviewed the outcome of 7 patients sustaining undisplaced femoral neck periprosthetic fractures associated with the Birmingham hip resurfacing procedure. All fractures presented within 4 months of initial surgery. All fractures were treated conservatively with a period of nonweight bearing. The 7 patients were assessed clinically and radiologically at a minimum of 16 months postfracture. All fractures had fully united. There was no evidence of impaired function or abnormal radiological findings after this conservative treatment strategy in 6 patients. One patient had marked femoral neck narrowing but no functional impairment.

The use of computer-assisted surgical navigation to prevent malalignment in unicompartmental knee arthroplasty.

We reviewed the outcome of 30 consecutive primary unicompartmental knee arthroplasties (UKAs) performed by a single surgeon over a 26-month period. All operations were performed to treat osteoarthritis of the medial compartment of the knee. Fifteen Allegretto (Sulzer, Winterthur, Switzerland) UKAs were implanted without computer navigation whereas 15 EIUS (Stryker-Howmedica, Allendale, NJ) UKAs were implanted using navigation. The patients were assessed clinically using the Oxford knee score and radiologically using long-leg weight-bearing films and non-weight-bearing computed tomography leg alignment films. No patients operated on were lost to follow-up. Unicompartmental knee arthroplasty performed with computer-assisted surgical navigation resulted in a more accurate and reproducible limb alignment than UKA performed without surgical navigation.

Subperiosteal aneurysmal bone cyst with associated bone marrow oedema: an unusual appearance.

A case of a subperiosteal aneurysmal bone cyst with adjacent bone marrow oedema is presented. Aneurysmal bone cysts have been well documented in the published literature; however, relatively few have been observed in a subperiosteal location, and associated bone marrow oedema in the absence of a demonstrable pathological fracture is a rare finding. Aneursymal bone cyst should be considered in the differential diagnosis of subperiosteal bone lesions and may be associated with bone marrow oedema.