Assessing the Clinical Value of Objective and Patient-Reported Audiovestibular Outcome Measures in the Risk Estimation of Systemic Cobalt Toxicity for Patients With a Metal-on-Metal Hip Implant.

OBJECTIVES: Based on limited evidence from case reports and small cohort studies of metal-on-metal (MoM) hip implant patients with presumed systemic cobalt (Co) toxicity, and a few animal studies on Co-induced damage to the otovestibular system, it was hypothesised that Co exhibits an ototoxic potential alongside other systemic manifestations. Preliminary investigations from our research group in MoM patients confirmed this assumption for the auditory system, whereas no signs of Co-induced vestibular impairment were detected, and a clear dose-response relationship between the auditory function and the blood Co levels was lacking. Therefore, the current study aimed to extend and validate these findings in a larger sample of MoM patients and control subjects, to explore the potential clinical value of audiovestibular outcome measures in the risk estimation of systemic Co toxicity in this patient population. DESIGN: Fifty patients (32 to 68 years) with a primary unilateral/bilateral MoM hip implant were matched for age, gender, and noise exposure to 50 nonimplanted control subjects. Both groups underwent the same protocol, consisting of an objective auditory [i.e., conventional and high-frequency audiometry, transient-evoked and distortion (TEOAEs and DPOAEs), auditory brainstem responses] and vestibular (i.e., cervical and ocular vestibular evoked myogenic potentials, horizontal and vertical video head impulse tests) test battery, a questionnaire inquiring auditory, balance, and general neurological symptoms, and a blood sample collection to determine the plasma Co concentration. RESULTS: The auditory test battery presented consistently higher audiometric thresholds in the MoM patient group, with group differences ranging from 2.1 to 5.7 dB in the lower frequencies (0.25 to 6.0 kHz) and from 4.6 to 9.3 dB in the high frequencies (8.0 to 14.0 kHz). Group differences at high frequencies were statistically significant ( p ≤ 0.001). Additionally, significantly lower TEOAE ( p = 0.009) and DPOAE ( p < 0.001) amplitudes were observed in the MoM patients when the better ear was included in the analysis, and more absent TEOAE and DPOAE responses were found between 1.0 and 4.0 kHz (0.008 ≤ p ≤ 0.039). Within the vestibular test battery, the MoM patients showed longer N1 and P1 ocular vestibular evoked myogenic potentials latencies for the left ear, and lower video head impulse test gains for the left anterior and right posterior semicircular canals (0.005 ≤ p ≤0.035). The patient-reported (questionnaire) outcome delivered no significant group differences ( p > 0.01). Six patients had elevated Co levels according to our local institutional threshold (>4 or 5 µg/l for unilateral or bilateral MoM hip implants, resp.), but their audiovestibular outcome measures did not differ significantly from those of the other patients. CONCLUSIONS: Corresponding to our preliminary investigations, the results indicate possibly Co-induced (predominantly high-frequency) auditory impairment, probably triggered by toxic damage to the cochlear structures. However, the low mean difference values, the lack of group differences for the patient-reported outcome measures, and the lack of any relationship with the blood Co levels strongly reduce the clinical relevance of these findings. Therefore, the risk of Co-induced ototoxic impairment is considered to be clinically negligible for the majority of MoM hip implant patients, and the use of auditory tests in the risk estimation of systemic Co toxicity should be decided on a case-by-case basis.

Arthroscopically assisted reduction of an unstable severe slipped capital femoral epiphysis: a case report.

Slipped capital femoral epiphysis (SCFE) is considered to be one of the most common disorders of the hip in children and adolescents. If left untreated, it may lead to progressive deformity, pain and decreased range of motion, and predisposes to early onset degenerative arthritis. Surgical treatment is advised, with in situ pinning across the physis being the gold standard for stable slips. Closed or open reduction can be considered in unstable or severe types. We report the arthroscopically assisted reduction of an unstable severe SCFE, followed by canulated screw fixation. A follow-up of 2.5 years shows an excellent clinical and acceptable radiological outcome. Our case demonstrates that arthroscopically assisted reduction of a slipped capital femoral epiphysis is feasible. Although the technique is technically challenging and requires familiarity with arthroscopy of the hip, it has some clear benefits as compared with both closed and open reduction techniques. Arthroscopically assisted reduction may therefore be a safe and effective treatment in unstable, severe SCFE.

Intra-abdominal fluid after hip arthroscopy: a case report.

The use of hip arthroscopy for diagnostic and therapeutic reasons has been steadily increasing over the last decade. It is considered a safe procedure, but some complications may be potentially life threatening. We present a case of intra-abdominal accumulation of irrigation fluid during hip arthroscopy in a 26-year-old patient. A literature review revealed only six other cases of fluid extravasation and its potentially dangerous consequences. The use of transparent sterile dressings during surgery might help early recognition of this unusual complication.

Endoscopic Treatment of Piriformis Syndrome Results in a Significant Improvement in Pain Visual Analog Scale Scores.

Purpose: To survey the clinical satisfaction of patients who have had an endoscopic piriformis release with a sciatic nerve neurolysis. Methods: Patients with piriformis syndrome (PS) who were treated with an endoscopic piriformis release combined with a sciatic neurolysis between 2013 and 2018 were identified. All patients had a minimum follow-up of 1 year. Patients were contacted by telephone in 201,9 whereby the rate of satisfaction and pain were evaluated with the Benson surgery scale and the visual analog scale (VAS). Results: The average duration of symptoms at first presentation was 34 months (range 16-54 months). Thirty-seven cases (82,2%) had an EMG that showed sciatic compression around the piriformis muscle. The average preoperative VAS pain score was 7.4 (± 0.8). The mean VAS score at the time of the survey was 1.9 (± 2.4). The difference in median preoperative and postoperative VAS was 6. Using the Wilcoxon signed-rank test, we found there was a significant improvement of VAS score (with P < .001). Using the Benson operative scale, we found that outcomes at the time of the survey were excellent in 23 patients (24 cases, 53.4%), good in 10 (22.2%), fair in 3 (6.7%), and poor in 8 (17.7%). Three patients with a poor result had a wrong diagnosis of PS and ended up needing treatment for a different diagnosis. In total, 33 patients answered affirmative on the question if they would undergo the procedure again. Apart from 3 local wound infections, no major complications were observed. Conclusions: Once a diagnosis is made, the endoscopic release of the piriformis tendon results in significant improvement in Pain VAS scores for patients with refractory symptoms despite conservative treatment. Level of Evidence: Level IV, therapeutic case series.

Hip arthroscopy: outcome and patient satisfaction after 5 to 10 years.

We retrospectively evaluated outcome, complications, reoperations and global patient satisfaction 5 to 10 years after an arthroscopy of the central compartment of the hip joint in 56 consecutive patients. All patients suffered from unsolved hip pain for at least 6 months, had a positive Flexion-Adduction-Internal rotation test (FADIR-test) and a normal radiograph. The mean follow-up was 72 months (range: 60 to 120 months). Thirty-seven patients were male and 19 female, with a mean age of 34 years (range, 17 to 59 years). Forty-five were improved (6 only temporarily) and 11 had no improvement (7 underwent total hip arthroplasty). Outcome and patient satisfaction differ significantly and are primarily determined by the grade of cartilage damage. Patient satisfaction 5 to 10 years after an arthroscopy of the central compartment of the hip is high: 80% (n = 45) of the patients would undergo the same procedure again.

Clinical benefit of joint distraction in the treatment of ankle osteoarthritis.

Irrespective of underlying mechanisms, the structural changes after joint distraction and the efficacy during several years validate the concept of joint distraction in the treatment of osteoarthritis. Therefore, joint distraction in the case of severe ankle osteoarthritis at relatively young age may be a treatment of choice. In the light of increased aging, and the limited life span of an endoprosthesis, evaluation of joint distraction in the case of knee and hip osteoarthritis is justified.

Clinical benefit of joint distraction in the treatment of severe osteoarthritis of the ankle: proof of concept in an open prospective study and in a randomized controlled study.

OBJECTIVE: Osteoarthritis (OA) is a degenerative, disabling joint disease that affects >10% of the adult population. No effective disease-modifying treatment is available. In the present study, we used joint distraction, a relatively new treatment in which mechanical contact between the articular surfaces is avoided while intraarticular intermittent fluid pressure is maintained, to treat patients with severe OA of the ankle. METHODS: Patients with severe ankle OA (n = 57) who were being considered for joint fusion (arthrodesis) were treated with joint distraction in an open prospective study. In addition, a randomized trial was performed in 17 patients to determine whether joint distraction had a better outcome than debridement. A standardized evaluation protocol (physical examination, assessment of pain, mobility, and functional ability) was used, and changes in radiographic joint space width and subchondral sclerosis were measured. Thirty-eight patients in the open study have been followed up for >1 year, with up to 5 years of followup in 7 of them (mean +/- SD followup 2.8 +/- 0.3 years). Patients in the randomized study have been followed up for 1 year. RESULTS: Significant clinical benefit was found in three-fourths of the 57 patients in the open prospective study. Most interestingly, the improvement increased over time. Radiographic evaluation showed increased joint space width and decreased subchondral sclerosis. Moreover, joint distraction showed significantly better results than debridement. CONCLUSION: The clinical benefit of joint distraction in the treatment of severe OA is proof of the concept. Although the followup remains relatively short and effects over time remain unpredictable, our study creates possibilities for the treatment of severe OA in general. Considering the high prevalence of OA and the lack of a cure for it, joint distraction as a treatment of severe OA may have great medical, social, and economic impact.