Luk Verhelst

Taper Corrosion in Modular Hip Prostheses: Analysis of Serum Metal Ions in 19 Patients

Recently, concerns have been raised about the use of metal-on-metal (MoM) implants. This has led to the recall of several resurfacing and large-diameter total hip arthroplasties (THA). Any MoM interface can be the cause of metal debris and adverse tissue reactions. We analyzed serum metal ions and HOOS scores in 19 of 306 patients treated with a THA with modular neck section. The only MoM interface in this particular implant is the taper between the neck and the stem. The articulating surface consists of a ceramic-on-polyethylene or ceramic-on-ceramic interface. As such, this study looks at the metal ion production from the modular neck section. One of 306 implants needed revision at 52-month follow-up because of an adverse reaction to metal debris (ARMD).

Reversed arthroscopic subacromial decompression for symptomatic irreparable rotator cuff tears: mid-term follow-up results in 34 shoulders.

BACKGROUND In the elderly, there is no guideline for the treatment of irreparable rotator cuff lesions. The results of open or arthroscopic repair are variable. We hypothesized that the use of a reversed arthroscopic subacromial decompression (RASD) would yield comparable results. MATERIAL AND METHODS Between January 2004 and December 2006, thirty-eight patients underwent a RASD for irreparable cuff tears in 39 shoulders. The surgical procedure consisted of a tenotomy of the long head of the biceps tendon, a debridement of the torn rotator cuff and a tuberoplasty, without violation of the coracoacromial arch and the acromion. RESULTS Thirty-three patients (age 69.9 +/- 7.3 years) were available for clinical and radiological evaluation of 34 shoulders (male/female ratio: 11/22), at a mean follow-up of 38 months (range: 21 months-52 months). Two of 33 patients had required revision surgery, and were excluded from further statistical analysis. In the remaining 31 patients (32 shoulders), the modified Constant-Murley score (CMS) improved from 34.9% +/- 11.6 to 84.0% +/- 11.6 (p < 0.0001). The preoperative mobility did not correlate with the final result. Preoperative pain was found to correlate negatively to the modified CMS at follow-up (p= 0.0038). Although the acromiohumeral height decreased with 2.58 mm +/- 1.68 and the severity of glenohumeral osteoarthritis increased with one grade (Samilson-Prieto classification), there was no correlation with the functional outcome. CONCLUSION We conclude that for irreparable rotator cuff tears in the elderly, excellent mid-term results can be achieved with a RASD.

The Morel-Lavallée Lesion as a Rare Differential Diagnosis for Recalcitrant Bursitis of the Knee: Case Report and Literature Review

A 72 year-old-male was referred to our institution with recalcitrant prepatellar bursitis. The injury was sustained after striking his right knee against a post whilst horse riding 9 months ago. Previous treatments included repeated aspiration and excision of the bursa with elastic compression bandaging. A diagnosis of a Morel-Lavallée internal degloving injury was made, and the lesion was satisfactorily managed by an internal quilting procedure to eliminate the potential dead space. A review of the literature reveals 29 published reports of Morel-Lavallée lesions with sufficient information for inclusion. These came from 14 separate countries with a total of 204 lesions in 195 patients. The most common anatomical location was the greater trochanter/hip (36%), followed by the thigh (24%) and the pelvis (19%). Most were managed surgically with evacuation of the haematoma and necrotic tissue followed by debridement, which was often repeated (36%). Conservative treatment with percutaneous aspiration and compression bandaging was the next most common treatment (23%). The knee was the fourth most common region affected (16%), and only 3 other lesions in the literature have been managed with a quilting procedure.

Extra-articular hip endoscopy: A review of the literature

The aim of this review is to evaluate the current available literature evidencing on peri-articular hip endoscopy (the third compartment). A comprehensive approach has been set on reports dealing with endoscopic surgery for recalcitrant trochanteric bursitis, snapping hip (or coxa-saltans; external and internal), gluteus medius and minimus tears and endoscopy (or arthroscopy) after total hip arthroplasty. This information can be used to trigger further research, innovation and education in extra-articular hip endoscopy.

Revising the Well-Fixed, Painful Resurfacing Using a Double-Mobility Head: A New Strategy to Address Metal-on-Metal Complications

Isolated revision of the femoral component of hip resurfacings to metal-on-metal (MoM) total hip arthroplasties has shown inferior results. We present a case series of well-fixed, painful MoM hips with elevated chromium and cobalt levels. An isolated femoral revision using a noncemented femoral component and a double-mobility head was performed. Patients were followed up for 6 months and showed excellent improvements in visual analog score and Hip dysfunction and Osteoarthritis Outcome Score (HOOS). Cobalt and chromium levels dropped at 6 weeks and were normal at 6 months. Although our follow-up is short, we feel that it is important to highlight this as a potential treatment strategy. This revision is less aggressive than traditional methods, eliminates the concerns from MoM bearings, and results in a stable construct.

Traumatic Posterior Lumbosacral Spondyloptosis in a Six-year-old: A Case Report and Review of the Literature

Study Design. Report of a traumatic posterior lumbosacral spondyloptosis in a 6-year-old. Objectives. To describe this type of fracture-dislocation in children. To evaluate a possible trauma mechanism. To evaluate specific characteristics of this type of lesion in children. Summary of Background Data. Fractures of the lumbar spine in children are rare. They are without exception caused by high-energy trauma. Fracture-dislocations mostly occur in the anterior direction. There are several reports of traumatic retrolisthesis in adults. To our knowledge, this is the first report of a retrolisthesis at the lumbosacral junction in a child. Methods. While sitting, a 6-year-old boy was hit by a truck. He presented with a flaccid paraparesis below L3. Radiologic investigations showed a posterior spondyloptosis at L5-S1. He was treated by open reduction with a pediatric posterior spinal instrumentation and posterolateral grafting. Results. After 1 year, the patient showed good radiologic fracture reduction and graft incorporation. There was no pain in the lumbar area. There was still a complete neurologic deficit beneath the L3 level, with loss of bladder and anal sphincter function. The patient was entered into a children’s rehabilitation program 5 weeks after surgery and is continuously improving his overall functional level. Conclusion. Traumatic retrolisthesis of the lumbosacral spine is extremely rare, especially in children. We believe shear force while sitting is the key traumatic factor. We believe a simple posterior fusion with posterolateral grafting is sufficient to stabilize the spine in children. Extensive soft tissue damage causes an elevated risk of infection. Because of root avulsion, the level of paralysis can be several levels higher than the level of dislocation.

Variations in Serum Electrolyte Concentrations and Renal Function After Therapeutic Hip Arthroscopy: A Pilot Study

PURPOSE The purpose of this study was to analyze changes in serum electrolyte concentration and renal function after hip arthroscopy. METHODS We studied 10 consecutive patients (4 men and 6 women; median age, 30.5 years [range, 20 to 50 years]) undergoing hip arthroscopy. Operating time, traction time, and perfusion volume of lactated Ringer solution (in milliliters) were recorded. Preoperative and postoperative levels of sodium (Na(+)), potassium (K(+)), cloride (Cl(-)), calcium (Ca(2+)), magnesium (Mg(2+)), phosphorous (P), creatinine, and blood urea nitrogen (BUN) were compared. RESULTS The median operating time was 80 minutes (range, 60 to 150 minutes). The median perfusion volume of lactated Ringer solution was 15,000 mL (range, 6,000 to 30,000 mL). The median traction time was 37.5 minutes (range, 30 to 105 minutes). None of the patients had postoperative complications develop. With a mean decrease of 0.84 +/- 0.68 mg/dL, only serum calcium levels were found to decrease significantly (P = .01). There was a mean decrease of 1.50 +/- 2.07 mEq/L in sodium concentrations (P = .06). Hip arthroscopy was associated with a mean postoperative decrease in creatinine and BUN concentrations of 0.05 +/- 0.06 mg/dL (P = .19) and 9.84 +/- 10.36 mg/dL (P = .13), respectively. Although the mean decrease in BUN concentration was important, this was not shown to be significant. No correlations were found between operating time, perfusion volume, and postoperative changes. CONCLUSIONS Lengthy therapeutic hip arthroscopy under high intra-articular pressure has only a minimal effect on electrolyte balance and renal function. We therefore conclude that performing routine preoperative and postoperative blood analysis of electrolyte concentrations and renal function is unnecessary. LEVEL OF EVIDENCE Level IV, therapeutic case series.