An international faculty of orthopaedic surgeons presented their work on the current challenges in hip surgery at the London Hip Meeting which was attended by over 400 delegates. The topics covered included femoroacetabular impingement, thromboembolic phenomena associated with hip surgery, bearing surfaces (including metal-on-metal articulations), outcomes of hip replacement surgery and revision hip replacement. We present a concise report of the current opinions on hip surgery from this meeting with appropriate references to the current literature

Aims

Hip fractures are a major cause of morbidity and mortality, and malnutrition is a crucial determinant of these outcomes. This meta-analysis aims to determine whether oral nutritional supplementation (ONS) improves postoperative outcomes in older patients with a hip fracture.

Peripheral nerve injury is an uncommon but serious complication of hip surgery that can adversely affect the outcome. Several studies have described the use of electromyography and intra-operative sensory evoked potentials for early warning of nerve injury. We assessed the results of multimodal intra-operative monitoring during complex hip surgery. We retrospectively analysed data collected between 2001 and 2010 from 69 patients who underwent complex hip surgery by a single surgeon using multimodal intra-operative monitoring from a total pool of 7894 patients who underwent hip surgery during this period. In 24 (35%) procedures the surgeon was alerted to a possible lesion to the sciatic and/or femoral nerve. Alerts were observed most frequently during peri-acetabular osteotomy. The surgeon adapted his approach based on interpretation of the neurophysiological changes. From 69 monitored surgical procedures, there was only one true positive case of post-operative nerve injury. There were no false positives or false negatives, and the remaining 68 cases were all true negative. The sensitivity for predicting post-operative nerve injury was 100% and the specificity 100%. We conclude that it is possible and appropriate to use this method during complex hip surgery and it is effective for alerting the surgeon to the possibility of nerve injury

We describe the clinical and radiological results of 120 consecutive revision hip replacements in 107 patients, using the JRI Furlong hydroxyapatite-ceramic-coated femoral component. The mean age of the patients at operation was 71 years (36 to 92) and the mean length of follow-up 8.0 years (5.0 to 12.4). We included patients on whom previous revision hip surgery had taken place. The patients were independently reviewed and scored using the Harris hip score, the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) and the Charnley modification of the Merle d’Aubigné and Postel score. Radiographs were assessed by three reviewers for the formation of new bone, osteolysis, osseointegration and radiolucent lines in each Gruen zone. The mean Harris hip score was 85.8 (42 to 100) at the latest post-operative review. The mean WOMAC and Merle d’Aubigné and Postel scores were 34.5 and 14.8, respectively. The mean visual analogue score for pain (possible range 0 to 10) was 1.2 overall, but 0.5 specifically for mid-thigh pain. There were no revisions of the femoral component for aseptic loosening. There were four re-revisions, three for infection and one for recurrent dislocation. Radiological review of all the femoral components, including the four re-revisions showed stable bony ingrowth and no new radiolucent lines in any zone. Using revision or impending revision for aseptic loosening as an end-point, the cumulative survival of the femoral component at ten years was 100% (95% confidence interval 94 to 100). We present excellent medium- to long-term clinical, radiological and survivorship results with the fully hydroxyapatite-ceramic-coated femoral component in revision hip surgery

Aims. Hip fractures are some of the most common fractures encountered in orthopaedic practice. We aimed to identify whether perioperative hypotension is a predictor of 30-day mortality, and to stratify patient groups that would benefit from closer monitoring and early intervention. While there is literature on intraoperative blood pressure, there are limited studies examining pre- and postoperative blood pressure. Methods. We conducted a prospective observational cohort study over a one-year period from December 2021 to December 2022. Patient demographic details, biochemical results, and haemodynamic observations were taken from electronic medical records. Statistical analysis was conducted with the Cox proportional hazards model, and the effects of independent variables estimated with the Wald statistic. Kaplan-Meier survival curves were estimated with the log-rank test. Results. A total of 528 patients were identified as suitable for inclusion. On multivariate analysis, postoperative hypotension of a systolic blood pressure (SBP) < 90 mmHg two to 24 hours after surgery showed an increased hazard ratio (HR) for 30-day mortality (HR 4.6 (95% confidence interval (CI) 2.3 to 8.9); p < 0.001) and was an independent risk factor accounting for sex (HR 2.7 (95% CI 1.4 to 5.2); p = 0.003), age (HR 1.1 (95% CI 1.0 to 1.1); p = 0.016), American Society of Anesthesiologists grade (HR 2.7 (95% CI 1.5 to 4.6); p < 0.001), time to theatre > 24 hours (HR 2.1 (95% CI 1.1 to 4.2); p = 0.025), and preoperative anaemia (HR 2.3 (95% CI 1.0 to 5.2); p = 0.043). A preoperative SBP of < 120 mmHg was close to achieving significance (HR 1.9 (95% CI 0.99 to 3.6); p = 0.052). Conclusion. Our study is the first to demonstrate that postoperative hypotension within the first 24 hours is an independent risk factor for 30-day mortality after hip fracture surgery. Clinicians should recognize patients who have a SBP of < 90 mmHg in the early postoperative period, and be aware of the increased mortality risk in this specific cohort who may benefit from a closer level of monitoring and early intervention. Cite this article: Bone Joint J 2024;106-B(2):189–194

Aims. Hospital case volume is shown to be associated with postoperative outcomes in various types of surgery. However, conflicting results of volume-outcome relationship have been reported in hip fracture surgery. This retrospective cohort study aimed to evaluate the association between hospital case volume and postoperative outcomes in patients who had hip fracture surgery. We hypothesized that higher case volume would be associated with lower risk of in-hospital and one-year mortality after hip fracture surgery. Methods. Data for all patients who underwent surgery for hip fracture from January 2008 to December 2016 were extracted from the Korean National Healthcare Insurance Service database. According to mean annual case volume of surgery for hip fracture, hospitals were classified into very low (< 30 cases/year), low (30 to 50 cases/year), intermediate (50 to 100 cases/year), high (100 to 150 cases/year), or very high (> 150 cases/year) groups. The association between hospital case volume and in-hospital mortality or one-year mortality was assessed using the logistic regression model to adjust for age, sex, type of fracture, type of anaesthesia, transfusion, comorbidities, and year of surgery. Results. Between January 2008 and December 2016, 269,535 patients underwent hip fracture surgery in 1,567 hospitals in Korea. Compared to hospitals with very high volume, in-hospital mortality rates were significantly higher in those with high volume (odds ratio (OR) 1.10, 95% confidence interval ((CI) 1.02 to 1.17, p = 0.011), low volume (OR 1.22, 95% CI 1.14 to 1.32, p < 0.001), and very low volume (OR 1.25, 95% CI 1.16 to 1.34, p < 0.001). Similarly, hospitals with lower case volume showed higher one-year mortality rates compared to hospitals with very high case volume (low volume group, OR 1.15, 95% CI 1.11 to 1.19, p < 0.001; very low volume group, OR 1.10, 95% CI 1.07 to 1.14, p < 0.001). Conclusion. Higher hospital case volume of hip fracture surgery was associated with lower in-hospital mortality and one-year mortality in a dose-response fashion. Cite this article: Bone Joint J 2020;102-B(10):1384–1391

The use of impaction bone grafting during revision arthroplasty of the hip in the presence of cortical defects has a high risk of post-operative fracture. Our laboratory study addressed the effect of extramedullary augmentation and length of femoral stem on the initial stability of the prosthesis and the risk of fracture.

Cortical defects in plastic femora were repaired using either surgical mesh without extramedullary augmentation, mesh with a strut graft or mesh with a plate. After bone impaction, standard or long-stem Exeter prostheses were inserted, which were tested by cyclical loading while measuring defect strain and migration of the stem.

Compared with standard stems without extramedullary augmentation, defect strains were 31% lower with longer stems, 43% lower with a plate and 50% lower with a strut graft. Combining extramedullary augmentation with a long stem showed little additional benefit (p = 0.67). The type of repair did not affect the initial stability. Our results support the use of impaction bone grafting and extramedullary augmentation of diaphyseal defects after mesh containment.

Effective concentrations of antibiotic in the fluid bathing implanted hip prostheses are essential to prevent infection by micro-organisms. Twenty patients undergoing total hip replacement were given one gram of Cephradine intramuscularly one hour before operation and one other received a single bolus of Cephradine intravenously before operation and one other received a single bolus of Cephradine intravenously before operation. The concentrations of antibiotic were greater and persisted longer in the tissue fluid than in the blood. The antibiotic was sufficient to inhibit most micro-organisms causing contamination. We recommend that Cephradine is given intramuscularly one hour before operation and at six-hourly intervals after operation until the drainage tubes and intravenous lines have been removed.

We have reviewed retrospectively 68 revisions of the femoral component in arthroplasties of the hip in 65 patients, using impaction bone grafting, at a median of three years (1 month to 6 years). We employed the cemented Exeter X-Change technique in 36 patients and the uncemented Bi-Metric allografting method in 32. The 37 bone defects were grade 3 or grade 4 on the Endo-Klinik classification.

The Mayo hip score improved from a mean of 32 (sd ± 18) to 62 (sd ± 15). Most (25) of the 34 complications occurred in grade-3 and grade-4 defects; nine were intraoperative diaphyseal fractures and eight fractures of the greater trochanter. All the fractures united.

The risk of intraoperative fracture was prevented by supporting the bone with wires in 16 hips, with reinforcement mesh in 18 and by a plate in six. Early migration of the stem of more than 10 mm during the first year indicated rotational instability; it occurred in three cases.

In difficult revision cases with large defects of the femoral bone, bone-impaction techniques carry a high risk of complications.

When cerebral palsy involves the entire body pelvic asymmetry indicates that both hips are ‘at risk’. We carried out a six-year retrospective clinical, radiological and functional study of 30 children (60 hips) with severe cerebral palsy involving the entire body to evaluate whether bilateral simultaneous combined soft-tissue and bony surgery of the hip could affect the range of movement, achieve hip symmetry as judged by the windsweep index, improve the radiological indices of hip containment, relieve pain, and improve handling and function.

The early results at a median follow-up of three years showed improvements in abduction and adduction of the hips in flexion, fixed flexion contracture, radiological containment of the hip using both Reimer’s migration percentage and the centre-edge angle of Wiberg, and in relief of pain. Ease of patient handling improved and the satisfaction of the carer with the results was high. There was no difference in outcome between the dystonic and hypertonic groups.

We developed a method of applying vibration to the impaction bone grafting process and assessed its effect on the mechanical properties of the impacted graft. Washed morsellised bovine femoral heads were impacted into shear test rings. A range of frequencies of vibration was tested, as measured using an accelerometer housed in a vibration chamber. Each shear test was repeated at four different normal loads to generate stress-strain curves. The Mohr-Coulomb failure envelope from which shear strength and interlocking values are derived was plotted for each test. The experiments were repeated with the addition of blood in order to replicate a saturated environment.

Graft impacted with the addition of vibration at all frequencies showed improved shear strength when compared with impaction without vibration, with 60 Hz giving the largest effect. Under saturated conditions the addition of vibration was detrimental to the shear strength of the aggregate. The civil-engineering principles of particulate settlement and interlocking also apply to impaction bone grafting. Although previous studies have shown that vibration may be beneficial in impaction bone grafting on the femoral side, our study suggests that the same is not true in acetabular revision.

Aims. Hip displacement, common in patients with cerebral palsy (CP), causes pain and hinders adequate care. Hip reconstructive surgery (HRS) is performed to treat hip displacement; however, only a few studies have quantitatively assessed femoral head sphericity after HRS. The aim of this study was to quantitatively assess improvement in hip sphericity after HRS in patients with CP. Methods. We retrospectively analyzed hip radiographs of patients who had undergone HRS because of CP-associated hip displacement. The pre- and postoperative migration percentage (MP), femoral neck-shaft angle (NSA), and sphericity, as determined by the Mose hip ratio (MHR), age at surgery, Gross Motor Function Classification System level, surgical history including Dega pelvic osteotomy, and triradiate cartilage status were studied. Regression analyses using linear mixed model were performed to identify factors affecting hip sphericity improvement. Results. A total of 108 patients were enrolled. The mean preoperative MP was 58.3% (SD 31.7%), which improved to 9.1% (SD 15.6%) at the last follow-up. NSA and MHR improved from 156.5° (SD 11.5°) and 82.3% (SD 8.6%) to 126.0° (SD 18.5°) and 89.1% (SD 9.0%), respectively. Factors affecting the postoperative MHR were preoperative MP (p = 0.005), immediate postoperative MP (p = 0.032), and history of Dega osteotomy (p = 0.046). Conclusion. We found that hip sphericity improves with HRS. Preoperative MP, reduction quality, and acetabular coverage influence femoral head remodelling. We recommend that surgeons should consider intervention early before hip displacement progresses and that during HRS, definite reduction and coverage of the femoral head should be obtained. Cite this article: Bone Joint J 2021;103-B(1):198–203

The Scottish National Blood Transfusion Service is the main provider of bone for grafting in Scotland. Bone is procured only from live donors, following very strict selection criteria, and we have investigated whether the amount being collected was adequate.

Our current harvest of approximately 1700 femoral heads per year is shown not to be enough to meet the future demand for revision surgery of the hip. Many more of these operations are being undertaken, and impaction grafting is being used increasingly.

We have calculated the predicted rates of collection and usage for the next four to five years so that we can expand our service in a controlled fashion.

In a double-blind, randomised study of thromboprophylaxis in patients undergoing total hip replacement, we compared a low-molecular-weight heparin with a placebo. Of the 120 patients enrolled, 112 completed the trial; 58 in the treatment group and 54 in the placebo group. Nine (16%) patients in the treatment group and 19 (35%) in the placebo group developed deep venous thrombosis, diagnosed by the 125I-fibrinogen uptake test (p < 0.02). Verification was obtained by phlebography in 86% of the patients. Prolonged surgery increased the risk of thrombosis in the placebo group but not in the treatment group (p < 0.05). There were significantly more cases of deep venous thrombosis in the placebo group during the first four postoperative days (p < 0.02). The groups did not differ with respect to peroperative and postoperative bleeding. Low-molecular-weight heparin offers safe and easily administered thromboprophylaxis in total hip replacement.