„Resurfacing“ des Humeruskopfes

Evaluation of periprosthetic bone mineral density and postoperative migration of humeral head resurfacing implants: two-year results of a randomized controlled clinical trial

BACKGROUND

Implant migration, bone mineral density (BMD), length of glenohumeral offset (LGHO), and clinical results were compared for the Copeland (Biomet Inc, Warsaw, IN, USA) and the Global C.A.P. (DePuy Int, Warsaw, IN, USA) humeral head resurfacing implants (HHRIs).

METHODS

The study randomly allocated 32 patients (13 women), mean age 63 years (range, 39-82 years), with shoulder osteoarthritis to a Copeland (n = 14) or Global C.A.P. (n = 18) HHRI. Patients were monitored for 2 years with radiostereometry, dual-energy X-ray absorptiometry, Constant Shoulder Score (CSS), and the Western Ontario Osteoarthritis of the Shoulder Index (WOOS). LGHO was measured preoperatively and 6 months postoperatively.

RESULTS

At 2 years, total translation (TT) was 0.48 mm (standard deviation [SD], 0.21 mm) for the Copeland and 0.82 mm (SD, 0.46 mm) for the Global C.A.P. (P = .06). Five HHRI were revised, and in the interval before the last follow-up (revision or 2 years), TT of 0.58 mm (SD, 0.61 mm) for revised HHRI was higher (P = .02) than TT of 0.22 mm (SD, 0.17 mm) in nonrevised HHRI. A comparison of TT at the last follow-up (revision or 2 years) found no difference between the HHRIs (P = .12). Periprosthetic BMD decreased initially but increased continuously after 6 months for both HHRIs. At 2 years, BMD was 48% higher around the Copeland HHRI (P = .005). The mean difference in LGHO was significantly higher for the Copeland than for the Global C.A.P. HHRI (P = .02). Clinical results evaluated with CSS and WOOS improved over time for both implant groups (P < .01), with no differences between the groups.

CONCLUSION

Both implants had only little migration and good clinical results. Periprosthetic BMD and LGHO both increased for the Copeland HHRI more than for the Global C.A.P HHRI.

Humeral resurfacing arthroplasty in combination with latissimus dorsi tendon transfer in patients with rotator cuff tear arthropathy and preserved subscapularis muscle function: preliminary report and short-term results

PURPOSE

Humeral resurfacing arthroplasty represents an alternative option to hemiarthroplasty for treatment of cuff tear arthropathy (CTA), with the advantages as follows: suitability for relatively young and high-demand patients because of preservation of bone stock and no loss of length, less invasive surgery, shorter operation time, no risk of periprosthetic stem fractures, and revision surgery can be undertaken easily. In the current study, resurfacing arthroplasty in combination with latissimus dorsi tendon transfer for CTA was performed. Three hypotheses: first, humeral resurfacing arthroplasty in combination with latissimus dorsi tendon transfer would improve the overall functional outcome in patients with CTA. Second, this combination would improve humeral external rotation. Third, this combination would improve abduction and shoulder elevation.

METHODS

Study was conducted as an observational case series. Fourteen patients (nine ♀ and five ♂) having CTA were included. Follow-up was carried out at the end of the 28th month for all patients. Constant Score was used for follow-up evaluation. Dorso-axillary approach was used for latissimus dorsi tendon transfer and ventral deltopectoral approach for Copeland resurfacing. Tendons were fixed to the greater tuberosity with two anchors.

RESULTS

The absolute Constant Score significantly improved from 34 preoperatively to 69 postoperatively, relative Constant Score from 42 to 91%, elevation from 95° to 138°, abduction from 88° to 147°, and external rotation from 16° to 22° (not significant).

CONCLUSION

Humeral resurfacing arthroplasty in combination with latissimus dorsi tendon transfer in patients having CTA with preserved subscapularis function has satisfactory short-term functional clinical outcome.

LEVEL OF EVIDENCE

IV.

[Cementless humeral surface replacement arthroplasty in patients less than 55 years of age]

BACKGROUND

Cementless humeral surface replacement arthroplasty is a viable treatment option for degenerative diseases of the shoulder joint. The aim of this prospective study was to analyse the results of this treatment option in patients younger than 55 years of age with different pathologies of the shoulder.

PATIENTS AND METHODS

Twenty-three patients (26 implants) treated with cementless humeral surface replacement arthroplasty were included in this study. Mean follow-up was 2.5 years (1-6 years). Ten patients had posttraumatic osteoarthritis, seven had primary osteoarthritis, and six had osteonecrosis. Patients were evaluated using the Constant score, shoulder motion, and subjective satisfaction.

RESULTS

The mean Constant score increased significantly from 33 points preoperatively (8-69 points) to 61 points postoperatively (25-83 points; p<0.0001), adjusted to age and gender from 38% (8-86%) to 70% (28-114%; p<0.0001). Significant improvement for the whole cohort was found regarding patients' pain, activity, mobility, shoulder flexion and abduction, and internal and external rotation (p<0.001). In one case, reoperation was necessary due to a superficial wound infection, and in another case, implant revision to a total shoulder replacement was performed because of glenoid erosion.

CONCLUSION

Cementless humeral surface replacement arthroplasty is a viable bone-preserving treatment option for young and active patients. Later conversion to total shoulder replacement is possible. Good clinical results, a low complication rate, and high patient satisfaction were found in the short and mid term. Long-term investigations are necessary to confirm these observations.