Two-Year Results of Ceramic-on-Ceramic Hip Resurfacing in an International Multicenter Cohort.

BACKGROUND: Hip resurfacing arthroplasty (HRA) is a bone-conserving alternative to total hip arthroplasty. We present the 2-year clinical and radiographic follow-up of a novel ceramic-on-ceramic HRA in an international multicenter cohort. METHODS: Patients undergoing HRA between September 2018 and January 2021 were prospectively included. Patient-reported outcome measures (PROMs) in the form of the Forgotten Joint Score, Hip Disability and Osteoarthritis Outcome Score Jr., Western Ontario and McMaster Universities Arthritis Index, Oxford Hip Score, and University of California, Los Angeles, Activity Score were collected preoperatively, and at 1 and 2 years postoperation. Serial radiographs were assessed for migration, component alignment, evidence of osteolysis or loosening, and heterotopic ossification formation. RESULTS: The study identified 200 patients who reached a minimum 2-year follow-up (mean 3.5 years). Of these, 185 completed PROMs follow-up at 2 years. There was a significant improvement in Hip Disability and Osteoarthritis Outcome Score (P < .001) and Oxford Hip Score (P < .001) between the preoperative, 1-year, and 2-year outcomes. Patients had improved activity scores on the University of California, Los Angeles, Active Score (P < .001), with 45% reporting a return to high-impact activity at 2 years. At 1 and 2 years, the Forgotten Joint Score was not significantly different (P = .38). There was no migration, osteolysis, or loosening of any of the implants. No fractures were reported over the 2-year follow-up, with only 1 patient reporting a sciatic nerve palsy. There were 2 revisions, 1 for unexplained pain at 3 months due to acetabular component malposition and 1 at 33.5 months for acetabular implant failure. CONCLUSIONS: The ceramic-on-ceramic resurfacing at 2 years postoperation demonstrates promising results with satisfactory outcomes in all recorded PROMs. Further long-term data are needed to support the widespread adoption of this prosthesis as an alternative to other HRA bearings.

No Difference in Hip Muscle Volumes and Fatty Infiltration in Those With Hip-Related Pain Compared to Controls.

Background: Little is known about muscle morphology in people with hip-related pain, without signs of femoro-acetabular impingement syndrome (FAIS). Identifying changes in hip muscle volume, fatty infiltrate and establishing relationships between muscle volume and strength, may provide insight into potential early treatment strategies. Purposes: To: (i) compare the volumes and fatty infiltrate of gluteus maximus, gluteus medius, gluteus minimis, tensor fascia latae and quadratus femoris between symptomatic and less-symptomatic sides of participants with hip-related pain; (ii) compare the volumes and fatty infiltrate of hip muscles between healthy controls and symptomatic participants; and (iii) explore relationships of hip muscle volumes to muscle strength and patient-reported outcome measures in people with hip-related pain. Study Design: Cross-sectional study. Methods: Muscle volume and fatty infiltrate (from magnetic resonance imaging), hip muscle strength, patient-reported symptoms, function and quality of life (QOL) were determined for 16 participants with hip-related pain (no clinical signs of FAIS; 37±9 years) and 15 controls (31±9 years). Using One Way Analysis of Co-Variance tests, muscle volume and fatty infiltrate was compared between the symptomatic and less-symptomatic sides in participants with hip-related pain as well as between healthy controls and symptomatic participants. In addition, hip muscle volume was correlated with hip muscle strength, hip-reported symptoms, function and QOL. Results: No differences in all the studied muscle volumes or fatty infiltrate were identified between the symptomatic and less-symptomatic hips of people with hip-related pain; or between people with and without hip-related pain. Greater GMED volume on the symptomatic side was associated with less symptoms and better function and QOL (ρ=0.522-0.617) for those with hip-related pain. Larger GMAX volume was associated with greater hip abduction and internal rotation strength, larger GMED volume was associated with greater hip extension strength, and larger QF volume was associated with greater hip abduction strength (rho=0.507-0.638). Conclusion: People with hip-related pain and no clinical signs of FAIS have hip muscle volumes that are not significantly different than those of matched pain-free controls or their less-symptomatic hip. Larger GMED muscle volume was associated with fewer symptoms and greater strength. Level of evidence: Level 3a.

In vitro cyclic testing of the Exeter stem after cement within cement revision.

Cement-within-cement (C-C) revision arthroplasty minimizes the complications associated with removal of secure polymethylmethacrylate. Failure at the interfacial region between new and old cement mantles remains a theoretical concern. This article assesses the cyclic fatigue properties of bilaminar cement mantles after C-C revision in vitro with the Exeter stem. Seven Exeter stems were cemented into Sawbone femurs and removed, and new undersized stems were cemented into the preserved mantle. The new constructs were loaded for 1,000,000 cycles at body temperature. Cement mantles were inspected postcycling. In no case was there delamination or failure of the cement mantle. The findings support the hypothesis that use of a thin revision cement mantle in conjunction with a polished double-tapered stem is not detrimental to the overall success of the implant. In the presence of a secure cement-bone interface in suitable patients, we recommend C-C revision techniques using double-tapered polished femoral stems.

THE ROLE of a BIKE FIT in CYCLISTS with HIP PAIN. A CLINICAL COMMENTARY.

Hip pathology is common amongst athletes and the general population. The mechanics of cycling have the potential to exacerbate symptomatic hip pathology and progress articular pathology in patients with morphologic risk factors such as femoroacetabular impingement. A professional fit of the bicycle to the individual which aims to optimize hip joint function can allow patients with hip pathology to exercise in comfort when alternative high impact exercise such as running may not be possible. Conversely improper fit of the bicycle can lead to hip symptoms in otherwise healthy individuals who present with risk factors for hip pain. Accordingly a bike fit can form part of the overall management strategy in a cyclist with hip symptoms. The purpose of this clinical commentary is to discuss hip pathomechanics with respect to cycling, bicycle fitting methodology and the options available to a physical therapist to optimize hip mechanics during the pedaling action.

Acute and Subacute Changes in Hip Strength and Range of Movement After Arthroscopy to Address Chondrolabral Pathology.

BACKGROUND: Hip pain is associated with reduced muscle strength, range of movement (ROM), and function. Hip arthroscopy is undertaken to address coexistent intra-articular pathologies with the aim of reducing pain and improving function. PURPOSE: To evaluate changes in strength and ROM in a cohort with chondrolabral pathology before surgery to 3 and 6 months after hip arthroscopy. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Sixty-seven individuals with hip pain who were scheduled for hip arthroscopy were matched with 67 healthy controls. Hip strength and ROM were collected preoperatively and at 3 and 6 months postoperatively. Repeated measures analysis of variance evaluated whether strength and ROM differed between limbs and among time points. Bonferroni post hoc tests determined differences in hip strength and ROM among testing times and between the hip pain group and matched controls. RESULTS: Hip extension, internal rotation (IR), external rotation (ER), and adduction (P < .040) strength were greater at 3 months after surgery; all directions, including flexion, abduction, and squeeze, were greater at 6 months (P < .015). Hip flexion ROM was greater at 3 months after surgery (P = .013). Flexion, IR, and ER ROM was greater at 6 months (P < .041). At 6 months, IR ROM (P = .003) and flexion, IR, and ER strength (P < .005) remained less than matched controls. CONCLUSION: With the exception of squeeze and flexion, all directions of hip strength and hip flexion ROM are significantly improved 3 months after arthroscopy to address chondrolabral pathology. By 6 months after arthroscopy, strength in all directions and flexion and rotation ROM are significantly improved in both limbs, but hip flexion, IR, and ER strength and IR ROM remain significantly less than that of healthy matched controls in both limbs.

Clinical features of people with hip-related pain, but no clinical signs of femoroacetabular impingement syndrome.

OBJECTIVES: Identifying impairments in hip range of motion (ROM) and muscle strength in people with hip-related pain, without signs of femoro-acetabular impingement syndrome (FAIS). STUDY AIMS: to determine if hip strength and ROM i) differs between the symptomatic and less-symptomatic hip of people with hip-related pain; and between people with hip-related pain and healthy controls; and ii) are associated with hip-related Quality of Life and pain. DESIGN: Cross-sectional study. SETTING: University laboratory. PARTICIPANTS: Thirty participants with hip-related pain who were awaiting hip arthroscopy (22 women; age = 37 ±â€¯10yrs), 32 healthy controls (19 women; age = 30 ±â€¯10yrs). MAIN OUTCOME MEASURES: Hip ROM, muscle strength, pain intensity and the Hip disability and Osteoarthritis Outcome Score (HOOS) were assessed. RESULTS: Less hip flexion ROM (p = 0.004), and extension (p = 0.004), abduction (p = 0.001) and internal rotation (IR) (p = 0.048) strength were measured on the symptomatic compared to non-symptomatic side. Hip-related pain participants had lower hip abduction strength (p = 0.045), and less flexion (p < 0.001), IR (p = 0.027) and external rotation (ER) (p = 0.019) ROM compared to controls. Less ER ROM (p = 0.03-0.04), and greater abduction (p = 0.03-0.04) and adduction strength (p = 0.02) were associated with better patient reported outcome measures. CONCLUSIONS: Specific impairments in hip ROM and strength were identified in people with hip-related pain but no FAIS.

Extraction of intramedullary nails by proximal stacked wire technique.

We describe the use of proximal stacked wires for the removal of an intramedullary nail in the context of difficult extraction and failed attempts by conventional methods. This percutaneous technique is particularly useful for the extraction of narrow cannulated or solid intramedullary nails after failure of removal by extraction bolt devices.

Early prosthetic complications after unipolar hemiarthroplasty.

BACKGROUND: In Australia, the most frequently used hemiarthroplasty prosthesis for the management of displaced intracapsular femoral neck fractures is the Uncemented Austin Moore (UAM). Despite concerns regarding poor functional outcomes and increased early revision rates associated with the UAM prosthesis, apprehension regarding the systemic side-effects of polymethylmethacrylate cement implantation in the elderly patient continues to influence prosthesis selection. This study examines the incidence of early prosthesis related complications after UAM and Cemented Thompson (CT) hemiarthroplasty procedures for the management of femoral neck fractures. METHODS: A multicentre retrospective review of charts and radiographs was conducted in 1118 unipolar hemiarthroplasty implantations to determine early complications associated with the CT and UAM prostheses over a 6-year period in five Queensland public hospitals. RESULTS: Intraoperative periprosthetic fractures were sustained in 11.8% of UAM and 1.8% of CT implantations (P < 0.0001). Intraoperative periprosthetic fractures were associated with an increased requirement for reoperation within 1 month of the index procedure (P = 0.05). No statistical difference in the incidence of intraoperative periprosthetic fractures could be observed between the hospitals participating, regardless of the proportional use of each prosthesis. Early dislocation rates were similar for the UAM and CT prostheses. The intraoperative mortality rate attributable to the use of polymethylmethacrylate cement during hip hemiarthroplasty was 1/738 (0.14%). CONCLUSIONS: The results of this study support the use of the CT prosthesis for the management of femoral neck fractures to reduce the high incidence of intraoperative periprosthetic fractures and associated requirements for early reoperation experienced with the UAM.

Diagnostic value of routine drain tip culture in primary joint arthroplasty.

BACKGROUND: Closed suction drainage after joint arthroplasty is common practice in many institutions. The purpose of this study was to determine the correlation between routine drain tip culture and the diagnosis of superficial or deep postoperative wound infection after primary knee and hip replacement. METHODS: Over a 12-month period, drain tips were retrieved and cultured in all patients who underwent unilateral primary total knee or hip replacement with the use of closed suction drainage. A total of 393 cultures was performed in 387 patients (145 hip replacements, 242 knee replacements). Patients were followed for an average of 8.9 months after surgery to assess for postoperative wound infection. RESULTS: Three patients had a positive drain tip culture, none of which were diagnosed with superficial or deep infection. Four patients (1%) were diagnosed with deep infection, 16 (4.1%) with superficial infection. No patient with either superficial or deep infection had a positive drain tip culture after their index procedure. The sensitivity of routine drain tip culture for the diagnosis of postoperative infection in primary joint replacement was 0% and specificity was 99.2%. CONCLUSIONS: These data do not support the practice of routine drain tip culture after primary hip or knee replacement for the diagnosis of postoperative infection.

Ultrasound-assisted hip arthroscopy.

We describe the use of intraoperative ultrasound for the safe development of arthroscopic portals during hip arthroscopy without the requirement for fluoroscopy. We find this technique consistently accurate, allowing the safe introduction of arthroscopic instruments into the hip with a very low rate of iatrogenic injury. We have further developed the technique for application to both central- and peripheral-compartment procedures. We now have a total experience of more than 700 procedures to date. With the described technique of ultrasound guidance for portal placement, fluoroscopy is required in fewer than 2% of hip arthroscopy procedures at our institution.

Bilateral Hip Joint Hylan G-F 20 Granulomatous Synovitis due to Viscosupplementation Injections.

We present the diagnosis of bilateral granulomatous inflammation of the hip joints associated with Hylan G-F 20 viscosupplementation injections. Clinicians recommending therapeutic Hylan injections for the management of hip arthritis should maintain clinical awareness regarding this potential complication.

Hip resurfacing arthroplasty and perioperative blood testing.

It is standard practice in many institutions to routinely perform preoperative and postoperative haemoglobin level testing in association with hip joint arthroplasty procedures. It is our observation, however, that blood transfusion after uncomplicated primary hip arthroplasty in healthy patients is uncommon and that the decision to proceed with blood transfusion is typically made on clinical grounds. We therefore question the necessity and clinical value of routine perioperative blood testing about the time of hip resurfacing arthroplasty. We present analysis of perioperative blood tests and transfusion rates in 107 patients undertaking unilateral hybrid hip resurfacing arthroplasty by the senior author at a single institution over a three-year period. We conclude that routine perioperative testing of haemoglobin levels for hip resurfacing arthroplasty procedures does not assist in clinical management. We recommend that postoperative blood testing only be considered should the patient demonstrate clinical signs of symptomatic anaemia or if particular clinical circumstances necessitate.

Ultrasonography-assisted arthroscopic proximal iliotibial band release and trochanteric bursectomy.

We describe arthroscopic iliotibial band release and trochanteric bursectomy assisted by intraoperative ultrasonography for accurate placement of arthroscopic portals and to ensure adequate decompression of the peritrochanteric space. We have found ultrasonography for endoscopic iliotibial band release a useful tool to assist with localizing the site and length of decompression.

The use of a ureteric stone basket for removing loose bodies at hip arthroscopy.

We present the use of a ureteric stone basket for arthroscopic removal of loose bodies from the hip joint. The technique is easy to perform and reduces the time required for loose body retrieval while minimizing the risk of iatrogenic damage to the cartilage surfaces of the joint.

Is there a need for routine follow-up after primary total hip arthroplasty?

BACKGROUND: The objective of routine outpatient assessment of well-functioning patients after primary total hip arthroplasty (THA) is to detect asymptomatic failure of prostheses to guide recommendations for early intervention. We have observed that the revision of THAs in asymptomatic patients is highly uncommon. We therefore question the need for routine follow-up of patients after THA. METHODS: A prospective analysis of an orthopaedic database identified 158 patients who received 177 revision THAs over a four-year period. A retrospective chart review was conducted. Patient demographics, primary and revision surgery parameters and follow-up information were recorded and cross-referenced with Australian Orthopaedic Association National Joint Replacement Registry data. RESULTS: One hundred ten THAs in 104 patients (average age 70.4 (SD 9.8 years)). There were 70 (63.6%) in total, 13 (11.8%) femoral and 27 (24.5%) acetabular revisions. The indications for revision were aseptic loosening (70%), dislocation (8.2%), peri-prosthetic fracture (7.3%), osteolysis (6.4%) and infection (4.5%). Only four (3.6%) were asymptomatic revisions. A mean of 5.3 (SD 5.2 and 1.9 (SD 5.3)) follow-up appointments were required before revision in patients with and without symptoms, respectively. The average time from the primary to revision surgery was 11.8 (SD 7.23) years. CONCLUSIONS: We conclude that patients with prostheses with excellent long-term clinical results as validated by joint registries, routine follow-up of asymptomatic THA should be questioned and requires further investigation. Based on the work of this study, the current practice of routine follow-up of asymptomatic THA may be excessively costly and unnecessary, and a less resource-intensive review method may be more appropriate.

Military static line parachute injuries in an Australian commando battalion.

BACKGROUND: The objective of this study was to define the casualty rates and anatomical distribution of injuries associated with military static line parachute (MSLP) descents conducted by an Australian Army Commando Battalion. This study was conducted to identify the strategies to reduce the injury burden related to MSLP activities. METHOD: A retrospective audit of injuries resulting from MSLP descents conducted by 4th Battalion Royal Australian Regiment (4 RAR) over a 13-month period. RESULTS: A total of 554 MSLP descents over the time period were reviewed. The overall casualty rate was 5.1%. For MSLP descents onto land drop zones, the incidence of injury requiring hospital admission was 2.6%. Paratrooper bodyweight was associated with increased risk of injury (P = 0.04) and hospital admission (P = 0.003), particularly when conducting descents onto land drop zones. MSLP descents conducted onto land were associated with a higher incidence of casualties when compared with those conducted into water drop zones (P = 0.001). CONCLUSION: During the period from February 2004 until February 2005, 4 RAR (Commando) experienced higher casualty rates during MSLP descents than expected when compared with the published report. Strategies to decrease the casualty rate of MSLP descents onto land drop zones may include more extensive ground training, increased frequency of MSLP descents, use of ankle braces and the development of purpose built drop zones. Consideration should be given to establishing a maximum bodyweight threshold for the conduct of MSLP activities or acquiring parachutes with decreased descent velocity for larger paratroopers.

In vitro analysis of exeter stem torsional stability.

The effect of cyclic loading on the torsional stiffness of a polished double-tapered femoral stem was investigated in vitro. Initial torsional stability was compared with torsional stability after cyclic loading. Stems were removed from the cement mantle and reinserted without the use of additional cement. Torsional stability was measured after reinsertion and after further cyclic loading. Subsidence of the stem was observed. No difference in torsional stiffness was observed during loading. No difference between the stiffness before extraction and after reinsertion was observed. Torsional stiffness of an Exeter stem does not decrease after axial subsidence under cyclic loading. Stability is retained after reinsertion into the original cement mantle. Debonding of the Exeter stem is not associated with rotational instability of the implant.

Elution and mechanical properties of antifungal bone cement.

The effect of the incorporation of amphotericin B into bone cement was examined; as literature suggests, this may be a feasible method for the treatment of periprosthetic fungal infections. Addition of antifungal increased the compressive strength of the bone cement--a statistically significant amount from 107 +/- 2.3 to 121 +/- 1.5 MPa. Elution of tobramycin and amphotericin B was quantified using ultraviolet-visible spectroscopy. Spectroscopy showed that 18% of the antibiotic was released during the first week, with most released in the first 24 hours. The elution of antifungal, however, was unable to be detected after 1 week, with less than 0.03% released. Amphotericin B does not weaken bone cement. Its inability to be delivered at a clinically significant dose gives no clear indication for its incorporation into cement.