Evaluation of Proximal Femoral Bone Mineral Density in Cementless Total Hip Arthroplasty: A 3-Arm Prospective Randomized Controlled Trial.

BACKGROUND: Femoral stem design affects periprosthetic bone mineral density (BMD), which may impact long-term survival of cementless implants in total hip arthroplasty (THA). The aim of this study was to examine proximal femoral BMD in 3 morphologically different uncemented femoral stem designs to investigate whether any particular design resulted in better preservation of BMD. METHODS: A total of 119 patients were randomized to receive a proximally coated collarless dual-taper wedge stem, a proximally coated collarless anatomic stem, or a fully coated collarless triple-taper stem. All surgeries were performed via the posterior approach, with mobilization on the day of surgery. Dual x-ray absorptiometry scans (Lunar iDXA, GE Healthcare) assessed BMD across the 7 Gruen zones preoperatively and at 6 weeks and 2 years postoperatively; if available, the native contralateral femur was also assessed as a control. Patient-reported outcomes of pain, function, and health were also assessed at these follow-ups. RESULTS: Averaged across all stems, BMD increased in zones 1 (2.5%), 2 (17.1%), 3 (13.0%), 5 (10%), and 6 (17.9%) at 2 years. Greater preservation of BMD was measured on the lateral cortex (zone 2) for both the dual-taper wedge and anatomic stems (p = 0.019). The dual-taper wedge stem also demonstrated preservation of BMD in the medial calcar (zone 7), while the anatomic and triple-taper stems declined in this region; however, the difference did not reach significance (p = 0.059). Averaged across all stems, BMD decreased in the mid-diaphysis region, distal to the stem tip (zone 4). All stems performed similarly at the time of final follow-up with respect to the patient-reported outcomes. CONCLUSIONS: This study demonstrated maintenance of femoral BMD after use of 3 different cementless femoral stem designs, with all achieving excellent improvements in patient-reported outcomes. The stems designed to load the proximal metaphyseal region resulted in higher BMD in that region. No significant stress-shielding was observed; however, longer follow-up is required to elucidate the impact of this finding on implant survivorship. LEVEL OF EVIDENCE: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Anaesthetic choice for hip or knee arthroplasty in New Zealand: Risk of postoperative death and variations in use.

Anaesthetic choice for large joint surgery can impact postoperative outcomes, including mortality. The extent to which the impact of anaesthetic choice on postoperative mortality varies within patient populations and the extent to which anaesthetic choice is changing over time remain under-explored both internationally and in the diverse New Zealand context. In a national study of 199,211 hip and knee replacement procedures conducted between 2005 and 2017, we compared postoperative mortality among those receiving general, regional or general plus regional anaesthesia. Focusing on unilateral (n=86,467) and partial (n=13,889) hip replacements, we assessed whether some groups within the population are more likely to receive general, regional or general plus regional anaesthesia than others, and whether mortality risk varies depending on anaesthetic choice. We also examined temporal changes in anaesthetic choice over time. Those receiving regional alone or general plus regional for unilateral hip replacement appeared at increased risk of 30-day mortality compared to general anaesthesia alone, even after adjusting for differences in terms of age, ethnicity, deprivation, rurality, comorbidity, American Society of Anesthesiologists physical status score and admission type (e.g. general plus regional: adjusted hazard ratio (adj. HR)=1.94, 95% confidence intervals (CI) 1.32 to 2.84). By contrast, we observed lower 30-day mortality among those receiving regional anaesthesia alone compared to general alone for partial hip replacement (adj. HR=0.86, 95% CI 0.75 to 0.97). The latter observation contrasts with declining temporal trends in the use of regional anaesthesia alone for partial hip replacement procedures. However, we recognise that postoperative mortality is one perioperative factor that drives anaesthetic choice.

MRI is not reliable in diagnosing of concomitant anterolateral ligament and anterior cruciate ligament injuries of the knee.

PURPOSE: There has been a renewed interest in the anterolateral structures of the knee, including description of the anterolateral ligament (ALL) as a distinct structure. Recognizing injury to the ALL is challenging, particularly given the subjective nature of physical examination. Consequently, focus has turned to magnetic resonance imaging (MRI) to reach a preoperative diagnosis of this region. The aim of this study was to examine the ability of 3-Tesla (3T) MRI to identify the ALL in ACL-injured patients compared to a matched control group of ACL-intact patients. The hypothesis was that the ALL would be more difficult to identify in ACL-injured patients compared to ACL-intact patients. METHODS: A prospective case control study was performed comparing 3T MRI scans of 63-patients with an ACL rupture with a control group of 64-patients without ACL injury. An experienced musculoskeletal radiologist and an orthopaedic surgeon evaluated the scans performed using standard knee protocols. The ALL was considered in three regions for analysis: femoral, meniscal, and tibial. The status of the ALL was determined as visualized or non-visualized, and the integrity was assessed as intact, attenuated, or focal discontinuity. RESULTS: The detection rate of at least a portion of the ALL was 41/64 (64%) in the control group and 45/63 (72%) in the ACL-injured cohort, respectively. The entire length of the ALL could only be identified in 15/64 (23%) of the control group and 13/63 (21%) of the ACL-injured cases. In both groups, the visibility of the ALL was poorest at the femoral region and greatest at the tibial regions. The ALL, when visualized, was deemed to be intact in 55/63 (87%) of cases. Although the inter-observer reliability was excellent for detection of the ALL in the control group (κ = 0.86), this decreased to only moderate reliability in the ACL-injured group (κ = 0.52). CONCLUSION: This study demonstrates that MRI alone should not be relied upon to make a diagnosis of ALL injury in the setting of concomitant ACL injury due to the inability to accurately visualize this structure consistently in its entirety. To make a diagnosis of ALL injury or anterolateral instability of the knee and clinical correlation remains essential. LEVEL OF EVIDENCE: Case-control study, Level III.

Synthetic devices for reconstructive surgery of the cruciate ligaments: a systematic review.

PURPOSE: The role of synthetic devices in the management of the cruciate ligament-injured knee remains controversial. The aim of this systematic review was to assess the safety and efficacy of synthetic devices in cruciate ligament surgery. METHODS: A systematic review of the electronic databases Medline, Embase, and The Cochrane Library (issue 1, 2014) on January 13, 2014, was performed to identify controlled and uncontrolled trials. Trials that assessed the safety and efficacy of synthetic devices for cruciate ligament surgery were included. The main variables assessed included rates of failure, revision, and noninfective effusion and synovitis. Patient-reported outcome assessments and complications were also assessed where reported. RESULTS: From 511 records screened, we included 85 articles published between 1985 and 2013 reporting on 6 synthetic devices (ligament augmentation and reconstruction system [Ligament Augmentation and Reconstruction System (LARS; Surgical Implants and Devices, Arc-sur-Tille, France)]; Leeds-Keio [Xiros (formerly Neoligaments), Leeds, England]; Kennedy ligament augmentation device [3M, St Paul, MN]; Dacron [Stryker, Kalamazoo, MI]; Gore-Tex [W.L. Gore and Associates, Flagstaff, AZ]; and Trevira [Telos (limited liability company), Marburg, Germany]). The heterogeneity of the included studies precluded meta-analysis. The results were analyzed by device and then type of reconstruction (anterior cruciate ligament [ACL]/posterior cruciate ligament [PCL]/combined ACL and PCL). The lowest cumulative rates of failure were seen with the LARS device (2.6% for ACL and 1% for PCL surgery). The highest failure rate was seen in the Dacron ACL group (cumulative rate, 33.6%). Rates of noninfective synovitis and effusion ranged from 0.2% in the LARS ACL group to 27.6% in the Gore-Tex ACL group. Revision rates ranged from 2.6% (LARS) to 11.8% (Trevira-Hochfest; Telos). Recent designs, specifically the LARS, showed good improvement in the outcome scores. The mean preoperative and postoperative Lysholm knee scores were 54 and 88, respectively; the mean preoperative and postoperative Tegner activity scale scores were 3.3 and 6, respectively. CONCLUSIONS: Preliminary results for newer-generation devices, specifically the LARS, show lower reported rates of failure, revision, and sterile effusion/synovitis when compared with older devices. LEVEL OF EVIDENCE: Level IV, systematic review of Level II through IV studies.

Bone grafts and bone substitutes for opening-wedge osteotomies of the knee: a systematic review.

PURPOSE: To establish the rate of use of various void fillers in the setting of opening-wedge osteotomy around the knee, the types of fixation used, and the rates of delayed union or nonunion related to these variables. In addition, this review addressed short-term to midterm outcomes and complication rates associated with such procedures. METHODS: The electronic databases Medline, Embase, and PubMed were searched using the methodology for systematic review as recommended by the Cochrane Collaboration. The search terms used were as follows: knee, osteotomy, knee joint, bone grafting, opening osteotomy, opening wedge, tibial osteotomy, femoral osteotomy, and bone substitute. We screened 1,383 articles and applied exclusion criteria. Fifty-six articles were included. RESULTS: We included 3,033 cases of osteotomy in 2,910 patients. The mean age of patients was 50 years, with a mean follow-up period of 42 months. Male patients comprised 52% of patients. The mean alignment change was 10.8°, shifting the mechanical axis to 5.1° valgus. Delayed union/nonunion rates were 2.6%, 4.6%, and 4.5% for autograft, allograft bone, and synthetic bone substitutes, respectively (P = .03). Delayed union/nonunion rates were significantly lower for autograft compared with allograft (P = .03) and for autograft and allograft compared with synthetic bone substitutes (P < .0001). Non-locking plates (n = 2,148) had a rate of delayed union/nonunion of 3.7% and a mean loss of correction over time of 0.5°. Locking plates (n = 681) had a rate of delayed union/nonunion of 2.6% and a loss of correction of 2.3°. All mean knee outcome scores improved, and an overall complication rate of 14% was found. CONCLUSIONS: Opening-wedge osteotomy had good short-term to midterm outcomes with acceptable complication rates. The lowest rates of delayed union/nonunion were in autograft bone-filled osteotomies. Plate type does not appear to affect osteotomy union or loss of correction. LEVEL OF EVIDENCE: Level IV, systematic review of Level I to IV studies.

Femoral head-neck junction reconstruction, after iatrogenic bone resection.

Arthroscopic over-resection of the head-neck junction during the treatment of a cam deformity can be a devastating complication and is difficult to treat. Large defects of the femoral head-neck junction (FHNJ) increase the risk of femoral neck fracture and can also affect hip biomechanics. We describe a case of an iatrogenic defect of the FHNJ due to excessive bone resection, and a previously non-described treatment using iliac crest autograft to restore femoral head-neck sphericity and hip joint stability. After protecting the femoral neck with an angled blade plate, the large anterior FHNJ defect was reconstructed using autogenous iliac crest bone graft; sphericity was restored by contouring the graft using spherical templates. Clinical and radiographic follow-up was performed up to 2 years. Results at 2 years showed no residual groin pain and normal range of motion. The Oxford Hip Score was 46/48, rated as excellent. Computed tomography (CT) scanning showed union of bone graft without resorption, and CT arthrogram indicating retained sphericity of the FHNJ without evidence of degenerative changes in the articular surface. This novel surgical technique can be used to restore the structural integrity and contour of the FHNJ that contains a significant anterior defect.

Ankle fractures: functional and lifestyle outcomes at 2 years.

BACKGROUND: Ankle fractures form a high proportion of the total number of fractures treated in New Zealand. International studies show that there are mixed functional outcomes with differing fracture types and subsequently differing lifestyle outcomes. METHODS: Fracture clinic records and orthopaedic admissions books for Wellington Public Hospital, Capital Coast Health, -Wellington, were retrospectively reviewed to gain a population of patients who sustained ankle fractures for the period January--December 1998. These patients were asked to fill in postal questionnaires detailing their current ankle function and lifestyle, two years after fracturing their ankle. The patients' radiographs were reviewed to classify the types of ankle fractures sustained. RESULTS: Of 141 patients that sustained ankle fractures, 74 were followed up 2 years after their ankle fracture. All fracture types averaged Olerud-Molander ankle scores of 71.1. Weber A fractures averaged ankle function scores of 90, Weber B fractures 80, and Weber C fractures 78. Four patients (5%) achieved 'poor' results, 12 (16%) patients achieved a 'fair' result, 30 (41%) patients gained a 'good' result, 27 (36%) patients attained 'excellent' results. Lifestyle outcomes were reflected in the patient's ankle function outcomes (P < 0.05). CONCLUSION: Patients who sustain ankle fractures can be expected to be still experiencing functional difficulties two years post-treatment.