Bilateral atraumatic femoral neck fractures resulting from transient osteoporosis of the hip.

A woman in her mid-30s presented to the orthopaedic team, unable to mobilise, shortly after her caesarean section. On questioning, she reported 10 weeks of atraumatic right hip pain. A radiograph revealed a displaced right subcapital neck of femur fracture. An MRI confirmed this, as well as identifying a minimally displaced left subcapital neck of femur fracture. She underwent a right total hip replacement and internal fixation of the left hip. A dual energy X-ray absorptiometry (DEXA) scan showed severe osteoporosis, and a diagnosis of transient osteoporosis of the hip was made. She was seen by the bone metabolism team and given calcium and vitamin D medication. Although atraumatic hip fractures are rare in young patients, disproportionate or persisting hip pain in pregnant patients should raise the index of suspicion and prompt further investigation in the form of an MRI. This will allow timely management of hip fractures and improve patient outcomes.

Anatomical pelvic loading of a monoblock polyethylene acetabular component.

AIMS: Uncemented metal acetabular components show good osseointegration, but material stiffness causes stress shielding and retroacetabular bone loss. Cemented monoblock polyethylene components load more physiologically; however, the cement bone interface can suffer fibrous encapsulation and loosening. It was hypothesized that an uncemented titanium-sintered monoblock polyethylene component may offer the optimum combination of osseointegration and anatomical loading. METHODS: A total of 38 patients were prospectively enrolled and received an uncemented monoblock polyethylene acetabular (pressfit) component. This single cohort was then retrospectively compared with previously reported randomized cohorts of cemented monoblock (cemented) and trabecular metal (trabecular) acetabular implants. The primary outcome measure was periprosthetic bone density using dual-energy x-ray absorptiometry over two years. Secondary outcomes included radiological and clinical analysis. RESULTS: Although there were differences in the number of males and females in each group, no significant sex bias was noted (p = 0.080). Furthermore, there was no significant difference in age (p = 0.910) or baseline lumbar bone mineral density (BMD) (p = 0.998) found between any of the groups (pressfit, cemented, or trabecular). The pressfit implant initially behaved like the trabecular component with an immediate fall in BMD in the inferior and medial regions, with preserved BMD laterally, suggesting lateral rim loading. However, the pressfit component subsequently showed a reversal in BMD medially with recovery back towards baseline, and a continued rise in lateral BMD. This would suggest that the pressfit component begins to reload the medial bone over time, more akin to the cemented component. Analysis of postoperative radiographs revealed no pressfit component subsidence or movement up to two years postoperatively (100% interobserver reliability). Medial defects seen immediately postoperatively in five cases had completely resolved by two years in four patients. CONCLUSION: Initially, the uncemented monoblock component behaved similarly to the rigid trabecular metal component with lateral rim loading; however, over two years this changed to more closely resemble the loading pattern of a cemented polyethylene component with increasing medial pelvic loading. This indicates that the uncemented monoblock acetabular component may result in optimized fixation and preservation of retroacetabular bone stock. Cite this article: Bone Joint J 2021;103-B(5):872-880.

Prevalence and characteristics of noise in a series of 282 ceramic-on-ceramic total hip arthroplasties.

OBJECTIVE: The aim of this study was to determine the prevalence of noise with ceramic-on-ceramic (COC) bearings in total hip arthroplasty (THA). We evaluated if patients wished be counseled about this and its potential consequences preoperatively. METHODS: Two hundred eighty-two primary cementless THAs were performed in 260 patients (124 males and 136 females), with a mean age 68.5 years. All patients completed a questionnaire. Minimum follow-up was 3 years. Statistical analysis was used to evaluate if patient variables influenced whether the patient experienced a noisy hip. RESULTS: Thirty-one (11%) of hips had an audible noise; 50% of these were 'squeaks.' The noise was mainly present upon standing up (74%) and walking (45%). None of the patients noted 'noise' on their consent forms. Fifty-five percent of the entire cohort would have preferred to have known about the possibility of a noisy hip before consenting, though no patients would have refused consent had they known about the noise preoperatively. No patients have sought financial compensation to date. There was no significant influence of gender (p=0.92), age (p=0.66), height (p=0.17), weight (p=0.99), or body mass index (p=0.29) on whether the patient experienced a noisy hip. CONCLUSION: No patient factor associated with noise could be identified. It is suggested that this issue be discussed preoperatively with all patients. In our cohort, this would satisfy the majority of patients' wishes and may additionally serve as important evidence in a malpractice claim. Therefore, it is suggested that the British Orthopaedic Association include 'the possibility of noise' in their consent form for THA.

Bisphosphonate-induced periprosthetic fracture: a cause of painful total hip arthroplasty.

Background. Cases have been reported in the literature of periprosthetic fractures associated with the use of bisphosphonates occurring in the long term following a Total Hip Replacement (THR). We report an interesting case of periprosthetic fracture secondary to bisphosphonate use only a few months after a THR. Case Report. A 72-year-old lady (on bisphosphonates for 10 years) underwent a THR for osteoarthritis. She was pain-free in the first four months postoperatively. Thereafter, she developed spontaneous onset of pain in the lateral aspect of her thigh and groin and found it difficult to weight-bear. X-rays and blood tests were unremarkable. An ultrasound and MRI scan showed no evidence of effusion/collection or periprosthetic fracture. A radionuclide bone scan showed an abnormal appearance of the right femoral shaft. A subsequent CT scan showed an oblique vertical split on the anterior surface of the upper right femoral shaft. This stress fracture was managed nonoperatively with protected weight bearing. She has progressed well with good clinical and radiological signs of fracture healing. Conclusion. This case is an important addition to our knowledge that bisphosphonate-induced periprosthetic stress fractures can be a cause of hip pain only a few months following a THR.

Posterior lumbar interbody fusion using cages, combined with instrumented posterolateral fusion: a study of 75 cases.

Posterior lumbar interbody fusion (PLIF) with cages can be combined with decompression of the spinal canal and with instrumented posterolateral fusion (IPLF) with pedicle screws, through a single posterior incision. The authors wanted to assess retrospectively the clinical and radiological outcome of PLIF + IPLF performed by the senior author. Between July 1997 and December 2003, 75 patients underwent PLIF with cages and IPLF with transpedicular instrumentation, for either degenerative disc disease, stenosis, spondylolisthesis or post-discectomy syndrome. The clinical outcome was evaluated according to the criteria of Kirkaldy-Willis. Flexion/extension radiographs and CT-scans were obtained in cases where there was any doubt about the fixation/fusion status. The mean age was 48.7 years (range: 30 to 75). The mean duration of follow-up was 29.17 months (range: 12 to 67). The clinical outcome was excellent or good in 85.3% of the patients. There were 4/75 patients (5.3%) who failed to return to their original occupation. Four posterolateral fusions were uncertain, but all anterior fusions succeeded: thus circumferential fusion was obtained in 71 out of 75 cases, or 94.6%. Three patients sustained a neurological complication, but only one was left with a partial drop foot. The results were comparable with similar studies. Therefore the authors recommend further use of PLIF + IPLF in painful lumbar degenerative spinal disease where conservative management has failed.

Posterior dislocation of the elbow as an unusual presentation after a total hip replacement: a case report.

INTRODUCTION: Posterior dislocation of the elbow is usually associated with trauma to the joint with a reported incidence of 3%to 6%. Chronic instability is usually symptomatic following the initial injury. CASE PRESENTATION: We report a case of posterior dislocation of the elbow occurring in a patient while using her arm to lift herself using a monkey pole on the second day following a total hip replacement. The dislocation was reduced under sedation in the ward. There were no signs or symptoms suggesting any joint hypermobility syndrome in the patient. Follow up 4 months following the injury revealed a complete recovery in the range of motion and a pain free elbow. There were no signs and symptoms of any instability. CONCLUSION: This is the first time such a case is reported in the literature. It certainly demonstrates that even in the absence of instability a patient can be predisposed to low energy dislocation of the elbow.