Mid-term results of a stemless ceramic on polyethylene shoulder prosthesis - A prospective multicentre study

INTRODUCTION

Early reports of stemless shoulder arthroplasty have shown promising clinical and radiological outcomes. The purpose of this study was to report on the mid-term results of an implant that utilises a ceramic humeral head.

METHODS

A prospective, consecutive, multicentre study of stemless shoulder prosthesis with a minimum of four years of follow-up was conducted between August 2009 and May 2012. The adjusted Constant-Murley Score (CMS), revision rate and presence of radiolucent lines were recorded at intervals.

RESULTS

A total of 207 patients were eligible for study inclusion; 62.8% were female and mean age was 64.8 years (range 30-86). Mean follow-up was 70.7 months (range 48-100), 73% underwent TSA and 27% hemiarthroplasty. The mean CMS improvement was 42.6 (p < 0.0001) at 48 months. Radiolucencies were present in 2.7% of humeral zones and 14% of glenoid zones at 48-month follow-up. The revision rate was 6.3% with rotator cuff failure (2.9%) the most common indication.

CONCLUSIONS

Mid-term results demonstrate that the studied stemless implant with a ceramic humeral head had clinical and radiological outcomes that are comparable to other reported studies.

Asymptotic inference for nearly unstable INAR(1) models

A sequence of first-order integer-valued autoregressive (INAR(1)) processes is investigated, where the autoregressive-type coefficient converges to 1. It is shown that the limiting distribution of the conditional least squares estimator for this coefficient is normal and the rate of convergence is n3/2. Nearly critical Galton–Watson processes with unobservable immigration are also discussed.

Fluctuation limit of branching processes with immigration and estimation of the means

We investigate a sequence of Galton-Watson branching processes with immigration, where the offspring mean tends to its critical value 1 and the offspring variance tends to 0. It is shown that the fluctuation limit is an Ornstein-Uhlenbeck-type process. As a consequence, in contrast to the case in which the offspring variance tends to a positive limit, it transpires that the conditional least-squares estimator of the offspring mean is asymptotically normal. The norming factor is n3/2, in contrast to both the subcritical case, in which it is n1/2, and the nearly critical case with positive limiting offspring variance, in which it is n.

Stemless shoulder prosthesis versus conventional anatomic shoulder prosthesis in patients with osteoarthritis: a comparison of the functional outcome after a minimum of two years follow-up

Background

The stemless shoulder prosthesis is a new concept in shoulder arthroplasty. To date, only a few studies have investigated the results of this prosthesis. The aim of this study was to investigate the clinical and radiological midterm results of this implant in comparison with a standard anatomic stemmed shoulder prosthesis.

Materials and methods

The Constant score, the DASH score, the active range of motion (abduction, anteversion, external rotation), and the radiological results were examined in 82 patients with primary osteoarthritis of the shoulder treated with either the Total Evolutive Shoulder System^® (Biomed, France) stemless shoulder prosthesis or the Affinis^® (Mathys, Switzerland) stemmed shoulder prosthesis to detect possible differences in the functional outcome and to evaluate radiological properties of the implants. Patients were examined before and 32 ± 4 months after surgery.

Results

There was no significant difference in the Constant scores of the groups treated with the stemless shoulder prosthesis (65.0 ± 11.0 points) and the stemmed shoulder prosthesis (73.2 ± 11.3 points; P = 0.162). The estimated blood loss (P = 0.026) and the mean operative time (P = 0.002) were significantly lower in the group with the stemless shoulder prosthesis.

Conclusions

The use of the stemless shoulder prosthesis yielded good results which, in a mid-term follow-up, were comparable with those provided by a standard anatomic shoulder prosthesis. Further investigations are needed regarding the long-term performance of this prosthesis.

Survival analysis of an asymmetric primary total knee replacement: a European multicenter prospective study

PURPOSE OF THE STUDY

This multicenter prospective study objective is to provide midterm results and 10-year survival analysis of the original Natural Knee-I System™ as experienced by a group of surgeons performing, within various settings, primary total knee replacement (TKR) in the general population.

HYPOTHESIS

The midterm experience with this TKR system in the hands of independent surgical teams can duplicate the satisfaction level that was already published by the designer's group itself.

MATERIAL AND METHOD

Two hundred and sixty-three primary TKR were performed by seven surgical teams (37 surgeons) and prospectively evaluated in four European countries. Mean age of the 263 patients (sex ratio, 2.7 females/1 male) was 69 years (range, 35-92) and diagnosis was primary osteoarthritis in 85%. For the 247 TKR with complete operative data, the approach was subvastus in 59%, posterior cruciate ligament was spared in 78%, patella was resurfaced in 56%, and 79% of reconstructions were totally cement-free. Fixation mode was only depending on the surgeon's choice.

RESULTS

At 76 months average follow-up (range 24-190 months), modified Hospital for Special Surgery knee mean score improved from 48 points preoperatively to 83 points. Four reoperations and five revision procedures were required for eight knees. Over the 14-year survey period, the overall revision rate burden was 2% and revision rate per 100 observed component/year, 0.32. At 10 years, survivorship (with revision for aseptic loosening as its end-point [two fully cementless knees]) was 98.6%.

DISCUSSION

Both this multicenter study and data drawn from national registers provided outcomes with equivalent level of satisfaction at equivalent follow-up to those reported by the NK-I prosthesis designer. There was no significant difference between revision rates of cemented, hybrid or cementless reconstructions.

CONCLUSION

In non-designer orthopaedists' hands, the Natural Knee-I System™, either with cemented or cementless fixation, provided satisfying midterm results as normally expected in primary TKR with such a modern modular prosthesis.

LEVEL OF EVIDENCE

Level IV. Prospective study.

Massive rotator cuff tears: functional outcome after debridement or arthroscopic partial repair

BACKGROUND

The surgical treatment of massive rotator cuff tears (RCT) is still controversial and can be based on a variety of different surgical repair methods. This study investigated the effectiveness of arthroscopic debridement or arthroscopic partial repair in patients with massive RCT.

MATERIALS AND METHODS

This prospective, randomized study involved forty-two patients with massive RCT (fatty infiltration stage 3 or 4) treated with either arthroscopic partial repair or arthroscopic debridement were selected to detect possible differences in functional outcome. Both groups were matched according to age and gender. Patients were examined before, and 16 +/- 3 and 24 +/- 2 months after surgery. The status of the rotator cuff repair was determined using ultrasonographic evaluation.

RESULTS

Regardless of the treatment group, postoperative results demonstrated highly significant improvements compared with preoperative values in most parameters. The overall Constant score in the partial repair group was superior to the outcome in the debridement group (P < 0.01, F = 8.561), according to better results in abduction (P < 0.01, F = 13.249), activity (P < 0.01, F = 21.391) and motion (P < 0.01, F = 4.967). All treatment groups had similar pain relief (P = 0.172, F = 1.802) and satisfaction, reflected in equal values of disabilities of the arm, shoulder and hand (DASH) score (P = 0.948, F = 0.004). Ultrasonography revealed structural failure of the partial rotator cuff repair in 52% at final follow-up.

CONCLUSIONS

During the follow-up period all patients in our series had good or satisfactory outcome after rotator cuff surgery. Regardless of high rates of structural failure of the partial rotator cuff repair, the results of arthroscopic partial rotator cuff repair demonstrated slightly better functional outcome than debridement.

Central motor deficits of the deltoid muscle in patients with chronic rotator cuff tears

PURPOSE OF THE STUDY

Previous surface EMG studies have shown that chronic rotator cuff tears (RCT) may be associated with a altered activation of adjacent shoulder muscles. The effect of RCT on central neuromuscular control mechanisms of the shoulder girdle muscles such as the deltoideus muscle (MD), a key muscle of shoulder function, has as yet not been studied in detail. This study investigated the cortico-spinal excitability of the MD to assess the effects of RCT on the central neuromuscular function of upper limb muscles.

MATERIAL AND METHODS

The motor evoked potentials (MEP) in response to transcranial magnetic stimulation of MD and first dorsal interosseus muscle (FDI) on both sides were obtained of six right-handed men with chronic, symptomatic, full-thickness RCT on the dominant sides. Stimulus response curves at four different levels were measured at two tasks (MD at rest and during activity).

RESULTS

Different interactions were found between stimulus intensity, task and side for MEP of the MD (F = 3.9, P = 0.03), indicating that MD excitability on the affected side were lower when compared with the non-affected side. No correlation was found between the correspondent MEP amplitudes of MD and FDI at rest (r = 0.1, P = 0.44) and MD activation (r = 0.3, P = 0.05) on the affected side whereas a correlation existed on the non-affected side at rest (r = 0.5, P = 0.007) and during activation (r = 0.8, P < 0.001).

CONCLUSIONS

These decreased cortico-motoneuronal excitability of the MD on the affected side seems to related to adaptive chan- ges in motor cortex as a consequence of chronic RCT. The data suggest an involvement of central mechanisms and seem to precede severe changes of osteoarthritis of the shoulder.

Small ubiquitin-like modifier 1 [corrected] mediates the resistance of prosthesis-loosening fibroblast-like synoviocytes against Fas-induced apoptosis

OBJECTIVE

To study the expression of small ubiquitin-like modifier 1 (SUMO-1) in aseptic loosening of prosthesis implants and to investigate its role in regulating the susceptibility of prosthesis-loosening fibroblast-like synoviocytes (FLS) to Fas-induced apoptosis.

METHODS

Specimens of aseptically loosened tissue were obtained at revision surgery, and the expression of SUMO-1 was analyzed by in situ hybridization. SUMO-1 levels in FLS were determined by quantitative polymerase chain reaction and Western blot analysis. Immunohistochemistry and confocal microscopy were used to study the subcellular localization of SUMO-1. The functional role of SUMO-1 in Fas-induced apoptosis of prosthesis-loosening FLS was investigated by small interfering RNA-mediated knockdown of SUMO-1 and by gene transfer of the nuclear SUMO-specific protease SENP1.

RESULTS

SUMO-1 was expressed strongly in aseptically loosened tissue and was found prominently at sites adjacent to bone. Prosthesis-loosening FLS expressed levels of SUMO-1 similar to the levels expressed by rheumatoid arthritis (RA) FLS, with SUMO-1 being found mainly in promyelocytic leukemia protein nuclear bodies. Knockdown of SUMO-1 had no effect on spontaneous apoptosis but significantly increased the susceptibility of prosthesis-loosening FLS to Fas-induced apoptosis. Gene transfer of the nuclear SUMO-specific protease SENP1 reverted the apoptosis-inhibiting effects of SUMO-1.

CONCLUSION

These data suggest that SUMO-1 is involved in the activation of both RA FLS and prosthesis-loosening FLS by preventing these cells from undergoing apoptosis. Modification of nuclear proteins by SUMO-1 contributes to the antiapoptotic effects of SUMO-1 in prosthesis-loosening FLS, providing evidence for the specific activation of sumoylation during their differentiation. Therefore, SUMO-1 may be an interesting target for novel strategies to prevent aseptic prosthesis loosening.

Central neuromuscular dysfunction of the deltoid muscle in patients with chronic rotator cuff tears

Background

Previous surface electromyogram (EMG) studies have shown that chronic rotator cuff tears (RCT) may be associated with a altered activation of adjacent shoulder muscles. The effect of RCT on central neuromuscular control mechanisms of the shoulder girdle muscles such as the deltoideus muscle (DM), a key muscle of shoulder function, has as not yet been studied in detail.

Materials and methods

This study investigated the corticospinal excitability of the DM to assess the effects of RCT on the central neuromuscular function of proximal upper limb muscles. The motor-evoked potentials (MEP) in response to transcranial magnetic stimulation of DM on both sides were obtained from patients with unilateral RCT and compared with healthy control subjects.

Results

In patients, stimulus response curves of DM demonstrated a bilateral hyperexcitability at rest and a hypoexcitability during voluntary activation (F = 3.82, P = 0.007).

Conclusions

The DM hyperexcitability may be related to alterations in the sensory output from the shoulder. The insufficient facilitation of the DM points toward a bilateral central activation deficit. These findings seem to be assigned to adaptive changes in the motor cortex as a consequence of chronic RCT, and the neuromuscular alteration of the DM should be considered when treating patients with RCT.

Short-term results after reversed shoulder arthroplasty (Delta III) in patients with rheumatoid arthritis and irreparable rotator cuff tear

The purpose of this study was to describe the outcome after reversed Delta III shoulder prosthesis in patients with rheumatoid arthritis (RA) and irreparable rotator cuff tear. Fifteen patients (17 joints) were prospectively analysed using the Constant-Murley score (CS). Comprehensive outcome measure was carried out by means of four widely used questionnaires as well as clinical and radiographic examinations at an average of 24.3 months postoperatively. The CS improved significantly from 19 to 59.5 points. The mental (MSC) and physical (PCS) component summary score of the Short Form 36 (SF-36) reached 108% and 77%, respectively, while the DASH (Disabilities of the Arm, Shoulder, and Hand) was 58% of a comparative norm population. Remaining deficits were documented by SPADI (Shoulder Pain and Disability; 54.4 points) and ASES (clinical and patient-orientated American Shoulder and Elbow Surgeons; 84.3 and 61.3 points, respectively). No radiological signs of loosening were found, but scapular notching occurred in four cases. Reversed arthroplasty provides a substantial improvement of shoulder function in patients with RA. The high incidence of notching is of concern.

The patient-rated wrist evaluation (PRWE): cross-cultural adaptation into German and evaluation of its psychometric properties

OBJECTIVE

To cross-culturally adapt the Patient-Rated Wrist Evaluation form (PRWE) into German (PRWE-G) and to evaluate its reliability and validity.

METHODS

A cross-cultural adaptation of the PRWE was carried out, according to established guidelines. 103 patients, who had undergone resection interposition arthroplasty (RIAP) for carpometacarpal osteoarthritis approximately 6.2 years earlier, completed a questionnaire booklet containing the PRWE-G, the Short Form 36 (SF-36), the Disabilities of Arm, Shoulder, and Hand (DASH); they also underwent clinical assessment with the Hand Function Index (HFI, Keitel) and Custom Score including grip and pinch strength tests. The results were used to assess the criterion and construct validity of the PRWE-G. To measure the re-test reliability, 51 patients completed a second PRWE-G within 2 weeks.

RESULTS

The test-retest reliability of the PRWE-G was acceptable for the pain and function sub-scales and for the global score, with intraclass correlation coefficients of 0.78-0.87. The PRWE-G showed a high internal consistency (Cronbach's alphas of 0.92-0.97 for the scales and the total score). The typical error of measurement for the global score was 8.1 points, giving a minimal detectable change (MDC<inf>95%</inf>) of approximately 22.5 points. The PRWE-G scores correlated well with those of the DASH (r=0.82, p<0.001) but less well with those of the physical component summary of the SF-36 (r=0.53, p<0.001) and not at all with the mental component summary scores of the SF-36 (r=0.04, p>0.05). The PRWE-G scores correlated moderately with certain clinical findings of the HFI, Custom Score, and grip/pinch strength tests (r=0.30-0.59, p<0.001).

CONCLUSION

The PRWE-G represents a valid and reliable instrument to evaluate self-rated outcome in German-speaking patients with hand and wrist pathology.

Hemi- versus bipolar shoulder arthroplasty for chronic rotator cuff arthropathy

Both bipolar and hemiarthroplasty have been used to treat rotator cuff arthropathy (RCA) of the shoulder in patients with low functional demands. In this study, 41 patients treated with either a bipolar or hemiarthroplasty were selected retrospectively to detect possible differences in the functional outcome and to evaluate radiological properties of the implants. Patients were examined before and 30 +/- 6 months after surgery. There were no differences in the Constant scores between the groups treated with hemiarthroplasty and bipolar arthroplasty, 58.9 +/- 13.1 points and 55.8 +/- 13.5 points, respectively (P = 0.457). We found a significant increase in abduction postoperatively in both groups (P = 0.041 bipolar, P = 0.000 hemiarthroplasty) but without statistical significance between the hemiarthroplasty and bipolar arthroplasty groups (P = 0.124, F = 2.6). This result is related in the bipolar group due to movement between the shell and inner head (P = 0.042) and in the hemiarthroplasty group due to movement between the humeral head component and the glenoid (P = 0.000). In conclusion, we found that both hemiarthroplasty and bipolar arthroplasty are effective treatment options for carefully selected patients with RCA and low functional demands, with no differences between the groups.

Cross-cultural adaptation, reliability and validity of the Patient Rated Elbow Evaluation (PREE) for German-speaking patients

OBJECTIVE

Patient-orientated questionnaires are important instruments for the assessment of outcome in the clinical environment and in musculoskeletal research. The objective of this study was to cross-culturally adapt the Patient Rated Elbow Evaluation (PREE) into German (PREE-G) and to test its reliability, validity and psychometric properties.

METHODS

The PREE was cross-culturally adapted for the German language, according to established guidelines. Fifty-six patients who had undergone elbow arthroplasty for osteoarthritis or chronic polyarthritis, on average 11 years previously, were assessed using the PREE-G, the Short Form 36 (SF-36), the Disabilities of Arm, Shoulder, Hand (DASH) and the modified American Shoulder and Elbow Surgeons (mASES) clinical evaluation.

RESULTS

The test-retest reliability (intraclass correlation coefficient) of the PREE-G was 0.80, and the internal consistency 0.96. The PREE-G correlated with the DASH (r = 0.73) and the physical component summary of the SF-36 (r = 0.57) but not with the mental component summary (r = -0.02). The PREE-G correlated moderately with certain clinical findings (mASES) (r = 0.36-0.54; p < 0.01).

CONCLUSION

The PREE-G represents a reliable and valid instrument to evaluate subjective outcome in German speaking patients with elbow pathology.

Periprothetische Frakturen bei Patienten mit rheumatoider Arthritis

Postoperative periprosthetic fracture is a rare but serious complication after joint replacement surgery. Due to poor bone quality, multiple joint involvement with the replacement of different joints and considerable comorbidity, the presence of rheumatoid arthritis is associated with a high risk of periprosthetic fractures. For the same reasons, periprosthetic fractures in patients with rheumatoid arthritis can be very difficult to treat, and their management often requires an interdisciplinary approach. On the basis of the current literature, the present work describes different aspects of the epidemiology of periprosthetic fractures, principles of their classification, different treatment options and the results of treatment of these fractures. Special attention is paid to the situation of patients with rheumatoid arthritis.

Mittelfristige Ergebnisse der zementfreien Schenkelhals-Endoprothese Typ CUT

AIM

The present work aims at evaluating the clinical and radiological midterm results of the femoral neck prosthesis CUT.

METHOD

67 femoral neck prostheses of the type CUT were implanted in 63 patients between 4/1999 and 5/2003 (average age 56 years). At an average follow-up time of 5.1 years (min.: 2.9; max.: 6.9) 53 patients with 57 CUT prostheses were examined clinically with the Harris hip score and radiologically. All together we determined the state of 64 CUT prostheses (96%).

RESULTS

The mean Harris hip score improved from 55 points preoperatively to 90.4 points at the last follow-up and is assessed as a good result. A total of 7 CUT prostheses (11%) had been revised. 3 CUT prostheses (4.7%) had been revised because of aseptic loosening, 2 (3.1%) because of persisting postoperative thigh pain, 1 (1.6%) because of vertical migration of an unsuitable CUT prostheses a few days after the operation and 1 (1.6%) because of septic loosening. The survival rate according to Kaplan-Meier was 89.1% at 5.1 years. If the femoral neck was resected too widely there was an increased rate of horizontal migration with aseptic loosening of the CUT prostheses.

CONCLUSION

In the midterm follow-up the CUT prosthesis shows a higher loosening rate as compared with cementless standard stems.

Schenkelhalsendoprothese Typ CUT

BACKGROUND

As the number of younger patients undergoing total hip arthroplasty is growing steadily, bone-saving implantation techniques are increasingly gaining in importance.

METHODS

Fifty-six femoral neck prostheses (type CUT, ESKA Implants, Lübeck, Germany) were implanted in 50 patients between 1999 and 2002 (average age 49 years). After a mean follow-up of 4.9 years (min.: 3.2, max.: 6.5), we determined the state of all the prostheses. Forty-four patients with 50 prostheses were examined clinically with the Harris hip score and were assessed radiologically.

RESULTS

The average Harris hip score improved from 48 points preoperatively to 93 points at the most recent follow-up examination. Of the 56 CUT prostheses, 6 (10.7%) had been revised. Four of these six cases (7.1%) required revision because of aseptic loosening. The radiological evaluation of these four cases revealed in three cases progressive horizontal migration with varization of the prosthesis, although the stem had been correctly positioned in primary surgery, with the femoral neck resected too widely or completely. After 4.9 years, the survival rate of the CUT prostheses is 88.4% according to Kaplan-Meier for a necessary exchange of the CUT prostheses as an endpoint.

CONCLUSION

The use of the CUT prosthesis can lead to good clinical and radiological results, but shows a higher loosening rate as compared with cementless standard stems. Further studies are necessary to determine if the CUT prosthesis is a real alternative to cementless standard stems.

Cross-cultural adaptation, reliability and validity of the German Shoulder Pain and Disability Index (SPADI)

OBJECTIVE

To cross-culturally adapt the Shoulder Pain and Disability Index (SPADI) from English into German, and to test the reliability and validity of the German version.

METHODS

Cross-cultural adaptation of the SPADI was performed according to international guidelines. One hundred and eighteen patients who had undergone shoulder arthroplasty, on average 4 yr previously, completed a questionnaire booklet containing the German SPADI, the Short Form 36 (SF-36), the Disability of the Arm, Shoulder and Hand (DASH) questionnaire, and the American Shoulder and Elbow Surgeons (ASES) questionnaire for the shoulder to assess SPADI's construct validity. One week later, they completed the SPADI again to assess test-retest reliability.

RESULTS

The six-step cross-cultural adaptation procedure revealed no major problems with the content or language. The intraclass correlation coefficients for the individual items of the SPADI were between 0.68 and 0.89, and that for the SPADI total score was 0.94. The SPADI total score showed a correlation of 0.61-0.69 with the SF-36 physical scales, of 0.88 with the DASH and of 0.92 with the ASES.

CONCLUSIONS

The German SPADI is a practicable, reliable and valid instrument, and can be recommended for the self-assessment of shoulder pain and function.

[Long-term results with the Harris-Galante press-fit-cup]

AIM

The present work aims at evaluating the clinical and radiological long-term results of the Harris-Galante press-fit cup.

METHOD

At an average follow-up time of 9.5 years (min. 9, max. 10.3) 123 patients with 138 Harris-Galante press-fit cups (HGP) were examined clinically and radiology. The clinical evaluation was done with the Harris hip score. Together with the HGP, which was inserted in all cases, five different femoral stems were implanted. A lateral approach, according to the technique of Watson-Jones, was used in all cases.

RESULTS

The mean follow-up Harris hip score was 89 of 100 points and is assessed as a good result. 7 cups (5%) were classed as being radiological loose, but only one case had also clinical symptoms. A total of 10 cups (6.8%) had to be revised. 3 cups (2 %) had to be revised because of aseptic loosening. This result represents a survival rate of 93.2% according to Kaplan-Meier.

CONCLUSION

The long-term clinical and radiological results of the Harris-Galante press-fit cup and there fixation method can assessed as good.

Gene transfer of tissue inhibitor of metalloproteinases-3 reverses the inhibitory effects of TNF-alpha on Fas-induced apoptosis in rheumatoid arthritis synovial fibroblasts

Apart from counteracting matrix metalloproteinases, tissue inhibitor of metalloproteinases-3 (TIMP-3) has proapoptotic properties. These features have been attributed to the inhibition of metalloproteinases involved in the shedding of cell surface receptors such as the TNFR. However, little is known about effects of TIMP-3 in cells that are not susceptible to apoptosis by TNF-alpha. In this study, we report that gene transfer of TIMP-3 into human rheumatoid arthritis synovial fibroblasts and MRC-5 human fetal lung fibroblasts facilitates apoptosis and completely reverses the apoptosis-inhibiting effects of TNF-alpha. Although TNF-alpha inhibits Fas/CD95-induced apoptosis in untransfected and mock-transfected cells, fibroblasts ectopically expressing TIMP-3 are sensitized most strongly to Fas/CD95-mediated cell death by TNF-alpha. Neither synthetic MMP inhibitors nor glycosylated bioactive TIMP-3 are able to achieve these effects. Gene transfer of TIMP-3 inhibits the TNF-alpha-induced activation of NF-kappaB in rheumatoid arthritis synovial fibroblasts and reduces the up-regulation of soluble Fas/CD95 by TNF-alpha, but has no effects on the cell surface expression of Fas. Collectively, our data demonstrate that intracellularly produced TIMP-3 not only induces apoptosis, but also modulates the apoptosis-inhibiting effects of TNF-alpha in human rheumatoid arthritis synovial fibroblast-like cells. Thus, our findings may stimulate further studies on the therapeutic potential of gene transfer strategies with TIMP-3.

Comprehensive assessment of clinical outcome and quality of life after total shoulder arthroplasty: usefulness and validity of subjective outcome measures

OBJECTIVE

To explore the physiometric and psychometric properties of clinical, generic, and condition-specific assessment instruments. To describe patients' outcome after total shoulder arthroplasty.

METHODS

Forty-three patients were assessed in a 5-6-year cross-sectional catamnesis.

RESULTS

With regard to shoulder joint stability, pain, general physical health, and mental health, the patients showed scores comparative to normative scores. Significant functional limitation was evidenced by low mean scores on the specific function scales (e.g., Disability of the Arm, Shoulder and Hand questionnaire score = 64.0, normative score = 86.6). There were high correlations among the joint-specific scales (up to 0.93) and moderate correlations between these and the generic and clinical scales. Factor analysis identified 3 different assessment domains.

CONCLUSION

The patients' quality of life (QOL) was high and not affected by impairment in some specific functional abilities. Physical QOL, mental QOL, clinical assessment, condition-specific measures, and generic measures were identified as separate domains, all of which are required for a comprehensive and sophisticated assessment in practical clinical routine.

Comprehensive assessment of clinical outcome and quality of life after resection interposition arthroplasty of the thumb saddle joint

OBJECTIVE

To explore the biometric and psychometric properties of clinical, generic, and condition-specific instruments and to assess quantitatively the outcome after resection interposition arthroplasty (RIAP) of the thumb saddle joint.

METHODS

One hundred three patients requiring 112 arthroplasties were assessed in a 4.5-7.7-year cross-sectional catamnesis by means of 4 widely used questionnaires and clinical and radiographic examinations.

RESULTS

In all dimensions of the Short Form 36 (SF-36), the outcome was equal or significantly better than expected by the norm. The Disability of the Arm, Shoulder and Hand questionnaire (DASH) revealed some small, mainly functional limitations (mean score 78.4, norm 86.4). The SF-36, the DASH, and the Patient Related Wrist Evaluation form (PRWE) correlated highly and loaded on the same factor. The Hand Function Index was independent of the clinical measurements (range of motion, strength, etc. on the specially designed Custom Form) and of the self rating.

CONCLUSION

Long-term followup of 112 RIAP patients showed excellent health and quality of life. A questionnaire set consisting of the SF-36, the DASH (or alternatively the short PRWE), and the Custom Form is proposed for the comprehensive and specific assessment of thumb joint conditions.

Comprehensive assessment of clinical outcome and quality of life after total elbow arthroplasty

OBJECTIVE

To assess quantitatively the outcome and to explore the physiometric and psychometric properties of clinical, generic, and condition-specific instruments after total elbow arthroplasty.

METHODS

Seventy-nine patients were assessed in a 6-19-year cross-sectional catamnesis by means of 6 widely used questionnaires, clinical examinations, and radiographic examinations.

RESULTS

With regard to pain, general physical health, and all the mental health dimensions of the Short Form 36 (SF-36), the patients showed scores comparable to normative values. Elbow joint stability and satisfaction were both good. Significant functional limitation was evidenced by the low mean scores of the SF-36 physical functioning measure (48.7, normative 69.9) and the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH) function measure (51.1, normative 89.3). The SF-36 physical component summary and the DASH correlated highly (r = 0.76) and, in factor analysis, loaded on the factor "physical unspecific." The patient and clinical modified American Shoulder and Elbow Surgeons questionnaire (mASES) correlated with the Patient Related Elbow Evaluation form (r = 0.92 with the patient mASES) and loaded on "physical specific." The SF-36 mental component summary loaded on "mental quality of life."

CONCLUSION

The patients' self-rated health, quality of life, and clinical outcome were good and were not affected by impairment in some specific functional abilities. A questionnaire set comprising the SF-36 and the patient and clinical mASES is proposed for the comprehensive and specific assessment of outcome after elbow arthroplasty.

Protease expression in interface tissues around loose arthroplasties

To determine whether cathepsins and matrix metalloproteinase-1 are involved in accelerating tissue destruction, we examined, immunohistochemically, the expression of matrix metalloproteinase-1 and cathepsins B, D, L, and X in periprosthetic synovial-like interface tissues from 14 patients with failed prosthetic hips and in the synovial membranes of hips from 18 patients with rheumatoid arthritis and 25 patients with primary osteoarthritis. The expression levels of all these proteases in the interface tissue were higher than in the synovial membrane of osteoarthritis. The expression levels of cathepsins B and X in the interface tissue were higher than in the rheumatoid synovium. The results show similarities in the expression patterns of cathepsins D and L and matrix metalloproteinase-1 between aseptic prosthetic loosening and rheumatoid arthritis. In addition, these data suggest that the impact of cathepsins B and X on tissue degradation is more pronounced in aseptic prosthetic loosening than in rheumatoid arthritis.

Strength and voluntary activation of the quadriceps femoris muscle at different severities of osteoarthritic knee joint damage

OBJECTIVE

Improvements of quadriceps motor deficits represent a major therapeutical target in knee osteoarthritis (OA). In the present study, we investigated changes in quadriceps function at different stages of osteoarthritic cartilage damage.

METHODS

Measurements of quadriceps voluntary activation (VA) and maximum voluntary contraction (MVC) were performed by a twitch interpolation technique and the total muscular capacity (TMC) was calculated as the ratio of MVC and VA. We assessed 68 patients (56.7+/-9.5 years) with stage II and 154 patients (65.6+/-6.0 years) with stage IV chondropathy. As controls, we used 85 age related healthy subjects (58.1+/-8.7 years).

RESULTS

While TMC was significantly lower in stage IV (90.6+/-43.7 Nm) than in stage II chondropathy (109.6+/-51.0) there were no differences in the MVCs between both groups. Quadriceps VA was even higher in stage IV (77.2+/-13.2%) than in stage II chondropathy (70.8+/-16.0%). In the controls, MVC, VA and TMC were significantly higher than in both OA groups.

CONCLUSION

We assume that a decrease of TMC might occur within the course of OA and, in consequence, VA increases to maintain quadriceps MVC.

Evaluation of wrist and hand handicap and postoperative outcome in rheumatoid arthritis

Functional instruments in rheumatology should use standardized procedures and should be quantifiable, valid, reliable, and responsive/sensitive to change. For most assessment tools, these aspects have been considered and tested. One of the most important questions in assessing hand involvement in patients with RA is what the single assessment should be used for. There could be a substantial difference should hand assessment be done in a routine way in a hand practice or should it be performed within scientific studies on disease progression or the effect of operative interventions. Among other points, answering this question has a significant impact on the time the patient has to spend with the tests and on the time the hand therapist or hand surgeon is involved with it. In addition to aspects such as accuracy, reliability, and validity, therefore, in some evaluation tools the time needed to perform the clinical examination and assessment of hand function has also been considered to be of importance. In addition, it has to be considered that description of the anatomic status, measurements of impairment, and assessment of disability cannot simply be replaced by each other, and even measurements of single aspects often are not sufficient. It has been stated, therefore, that the combination of different discrete hand-function assessment methods provides a more complete picture of hand ability. Moreover, although better responsiveness of disability outcome measures over impairment measures has been demonstrated previously (eg, in patients treated for Colle fracture), the relationship between disability and impairment measures is not clearly established. Although some studies reported significant correlations between impairment and disability tests, other studies showed only poor or moderate correlations between disability scores, impairment, and disease activity measures when rheumatoid hands were assessed. It has been concluded that the relationship between impairment and disability is not straightforward. The new ICF-model addresses these two levels of health-related quality of life by different concepts of assessment. Because impairment reflects the consequences of the disease at the organ level, whereas disability reflects the consequences of the disease for functional performance and activity, for comprehensive assessment of hand handicap, measurement of disability is more comprehensive and closer to the patient's needs for performing ADLs.

[Long-term results with the cementless CLS stem in hip replacement]

OBJECTIVE

The present work aims at evaluating the clinical and radiological long-term results of the cementless CLS stem in hip replacement.

METHOD

Sixty-six consecutively operated patients were examined clinically and radiologically at an average follow-up time of 10.7 (7.6 - 13.8) years. The clinical evaluation was done with the Merle d'Aubigné and the Harris hip scores. The radiological evaluation included the evaluation of radiolucencies as well as the occurrence of heterotopic ossifications.

RESULTS

A total of four stems had to be revised (two infections, two periprosthetic fractures). No stem revision had to be done because of aseptic loosening. This results in a survival rate of 94.5% according to Kaplan-Meier. The mean Merle d'Aubigné scores increased from 9.0 preoperatively to 16.0 points at follow-up. The mean follow-up Harris hip score was 87.3 points. Periprothetic osteolytic zones were observed in 45% of the cases, particularly in the Gruen zones 1 and 7. These osteolytic zones were mainly found in connection with cementless polyethylene cups.

CONCLUSION

The results of this study confirm the positive short and medium-term results with the CLS stem in a long-term process. The formerly described phenomenon of the residual thigh pain with cementless stems was clearly minimized.

Kinesthetic sense of the shoulder in patients with impingement syndrome

A proprioceptive deficit is an important determinant of disability in various shoulder disorders, such as instability and osteoarthrosis. In 15 patients with impingement syndrome stage II (Neer 1983), who were treated by arthroscopic subacromial decompression, we measured movement sense by determining threshold levels for the perception of motion of the shoulder. The patients were placed in a specially designed chair allowing continuous passive motion of the shoulder joint, while avoiding cutaneous, auditory and visual stimuli. To assess movement detection thresholds, passive abduction movements of the shoulder were performed at a starting angle of 60 degrees, an amplitude of 10 degrees and an angular velocity of 1.3 degrees/s. Before surgery, all patients had higher threshold levels for the perception of motion in their affected shoulders then in the other side. After decompression, proprioception had improved on the decompressed side, but was unchanged on the other side.

Higher susceptibility to Fas ligand induced apoptosis and altered modulation of cell death by tumor necrosis factor-alpha in periarticular tenocytes from patients with knee joint osteoarthritis

The aim of the present study was to investigate the expression of Fas in periarticular tenocytes of patients with osteoarthritis (OA) and to study their susceptibility to Fas ligand-mediated apoptosis. Tendon samples were obtained from the quadriceps femoris muscle of patients with knee OA and used for histological evaluation, for immunohistochemical detection of Fas, and to establish tenocyte cultures. The expression of Fas mRNA was determined by quantitative PCR. Levels of soluble Fas and soluble tumour necrosis factor (TNF) receptor I were measured using ELISA. Apoptosis was induced with recombinant human Fas ligand and measured by a histone fragmentation assay and flow cytometry. The effects of TNF-alpha were studied by stimulation with TNF-alpha alone or 24 hours before the induction of apoptosis. Tendon samples from non-OA patients were used as controls. Histological evaluation revealed degenerative changes in the tendons of all OA patients but not in the controls. Fas was detected by immunohistochemistry in all specimens, but quantitative PCR revealed significantly higher levels of Fas mRNA in OA tenocytes. In contrast, lower levels of soluble Fas were found in OA tenocytes by ELISA. OA tenocytes were significantly more susceptible to Fas ligand induced apoptosis than were control cells. TNF-alpha reduced the Fas ligand induced apoptosis in OA tenocytes but had no effects on control tenocytes. These data suggest that knee OA is associated with higher susceptibility of periarticular tenocytes to Fas ligand induced apoptosis because of higher expression of Fas but lower levels of apoptosis-inhibiting soluble Fas. These changes may contribute to decreased cellularity in degenerative tendons and promote their rupturing. The antiapoptotic effects of TNF-alpha in OA tenocytes most likely reflect regenerative attempts and must be taken into account when anti-TNF strategies are considered for OA.

Osteoclast-independent bone resorption by fibroblast-like cells

To date, mesenchymal cells have only been associated with bone resorption indirectly, and it has been hypothesized that the degradation of bone is associated exclusively with specific functions of osteoclasts. Here we show, in aseptic prosthesis loosening, that aggressive fibroblasts at the bone surface actively contribute to bone resorption and that this is independent of osteoclasts. In two separate models (a severe combined immunodeficient mouse coimplantation model and a dentin pit formation assay), these cells produce signs of bone resorption that are similar to those in early osteoclastic resorption. In an animal model of aseptic prosthesis loosening (i.e. intracranially self-stimulated rats), it is shown that these fibroblasts acquire their ability to degrade bone early on in their differentiation. Upon stimulation, such fibroblasts readily release acidic components that lower the pH of their pericellular milieu. Through the use of specific inhibitors, pericellular acidification is shown to involve the action of vacuolar type ATPases. Although fibroblasts, as mesenchymal derived cells, are thought to be incapable of resorbing bone, the present study provides the first evidence to challenge this widely held belief. It is demonstrated that fibroblast-like cells, under pathological conditions, may not only enhance but also actively contribute to bone resorption. These cells should therefore be considered novel therapeutic targets in the treatment of bone destructive disorders.

[The influence of the drain suction in knee arthroplasty]

PROBLEM

In a prospective randomised clinical study, we investigated the impact of drain-suction on the post-operative blood loss and on both clinical and laboratory parameters after knee replacement operations.

PATIENTS AND METHOD

In this study, 116 patients with unilateral implantation of knee replacements were evaluated. The patients' average age was 71.2 years. The operation was carried out mostly without tourniquet application. All patients received two wound drains, 57 with and 59 without suction. The postoperative blood loss as well as clinical and laboratory parameters were assessed.

RESULTS

The average peri-operative blood loss amounted to 338 ml. The post-operative blood loss in the group without drain suction was 436 ml and 528 ml in the group with suction. No significant differences could be found concerning the hemoglobin values pre-operatively and on the first and seventh post-operative day, the drainage quantity 12, 24, 36, and 48 hours post-operatively, the wound healing and the CRP. Six patients in the group without and five patients in the group with drain-suction had to receive blood transfusions.

DISCUSSION

The application of suction on the drainage system had no significant impact on the post-operative blood loss and the postoperative course. In nine out of ten cases no homologous blood was needed.

Quadriceps muscle function after high tibial osteotomy for osteoarthritis of the knee

In patients with osteoarthritis of the knees, quadriceps muscle dysfunction is an early and common clinical feature and an important determinant of disability. In the current study, changes in quadriceps muscle strength and voluntary quadriceps muscle activation after high tibial osteotomies for primary osteoarthritis of the knee in 19 patients were investigated. Quadriceps muscle function was assessed during different degrees of isometric maximum voluntary contraction using a specially built chair. One year after surgery all patients had reexamination of their surgically treated and contralateral knees. Voluntary activation and maximum voluntary contraction values of the followup assessment were significantly lower in the surgically treated knees compared with the preoperative assessment. In the contralateral knees, there were no differences between preoperative and followup measurements. High tibial osteotomy is an extraarticular operative therapeutic approach to treatment of osteoarthritis of the knee that does not lead to improvement of quadriceps muscle function. Because there is evidence that quadriceps sensorimotor dysfunction is important not only for the disability in osteoarthritis of the knee, but also for progression of the disease, knee function may be worsened by high tibial osteotomy in some patients.

Evaluation of quadriceps strength and voluntary activation after unicompartmental arthroplasty for medial osteoarthritis of the knee

INTRODUCTION

In early and moderate stages of osteoarthritis (OA) of the knee, arthrogenous muscle inhibition (AMI) is an important factor for the initiation and the progression of the disease. Although AMI has been shown to be reduced after physiotherapeutical exercises resulting in significant improvements in disability, implantation of unicondylar knee arthroplasties is much provided in these stages of OA. Therefore, in the present study we investigate changes in quadriceps muscle after implantation of such prostheses as compared to physiotherapeutical treatment, alone.

METHODS

In eighteen patients with bilateral moderate knee OA, who were treated with unicondylar knee arthroplasty we investigated voluntary activation (VA) and maximum voluntary contraction (MVC) of the quadriceps femoris muscle. There were 7 males and 11 females, the mean age at time of operation was 67 years (range 58-76 years). Measurements on both sides were performed preoperatively and 18 months postoperatively using the twitch-interpolation technique.

RESULTS

Follow-up assessment revealed a significant VA and MVC increase in both the surgically treated knees and in the contralateral knees treated by physiotherapy alone. However, VA and MVC improvements were significantly higher in the operated on knees than in those treated by physiotherapy alone.

DISCUSSION

Both physiotherapeutical exercise and unicondylar knee replacements lead to an improvement of quadriceps motor function in knee OA. The greater improvement in knees with both knee replacement and physiotherapy might be related to the intraoperative removal of arthritic tissue in these knees.

Strength and motion after hemiarthroplasty in displaced four-fragment fracture of the proximal humerus: 27 patients followed for 1-6 years

We evaluated 27 patients with shoulder hemiarthroplasty after displaced four-fragment fracture of the proximal humerus after mean 4 (1-6) years. Isometric strength measurements (Kintrex) and three-dimensional motion analysis (Elite-System) were performed on the operated and unoperated shoulders. Clinical assessment was based on Constant's score and Neer's scoring system. The isometric strength of the operated and unoperated sides were 22 (SD 8.6) Nm and 24 (SD 5.9) Nm in abduction and 48 (SD 14) Nm and 65 (SD 21) Nm, respectively in adduction (the latter was statistically significant). Motion analyses at follow-up showed a mean reduction in glenohumeral movement. Increases in acceleration and deceleration of the acromion at the operated side were noted, indicating a change in glenohumeral rhythm during maximal abduction. The Constant score was 45 (SD 15) points with a significant reduction in the range of motion. 15 patients had some degree of heterotopic ossification. On the basis of our findings, the impaired function seems to be caused by reduced glenohumeral mobility rather than muscle strength. We also found a better outcome after early than late hemiarthroplasty.

[History of German orthopedics 1989-2001]

The present article describes essential aspects of the development of German orthopedics from 1989 to 2001. Special attention is given to the unification of the two German orthopedic groups after the political turnaround in the German Democratic Republic and the resultant changes in the landscape of German orthopedics. In addition, further milestones in the development of German orthopedics during the last 10 years are presented, e.g., the formation of the Alliance of German Orthopedists, the establishment of various sections of the DGOT (German Association of Orthopedics and Traumatology) as well as the main focus of scientific activity in the past few years.

Have the new drugs relieved the burden of the orthopedic surgeon?

Rheumatoid arthritis (RA) represents a chronic joint inflammation that leads to destructive lesions of joint cartilage and periarticular bone. Increased understanding of the molecular and cellular mechanisms of RA and recent advantages in molecular technology have resulted in new antirheumatic drugs such as tumor necrosis factor-alpha blockers, inhibitors of interleukin-1, and novel disease-modifying antirheumatic drugs such as leflunomide. This review summarizes the important effects of the novel antirheumatic drugs and their potential impact on the work of orthopedic surgeons. The ability of these agents not only to improve the clinical signs and symptoms of RA but also to prevent progressive joint damage promises support to the work of orthopedic surgeons and to the interdisciplinary treatment of RA patients. The challenge, however, will be to conduct studies that show the concrete way in which the single drugs may best relieve the burden of the orthopedic surgeon.

Development and characteristics of a synovial-like interface membrane around cemented tibial hemiarthroplasties in a novel rat model of aseptic prosthesis loosening

OBJECTIVE

Aseptic prosthesis loosening (APL) is related to the formation and aggressive growth of a synovial-like interface membrane (SLIM) between prosthesis and bone. However, investigation of the early phases of SLIM development in humans presents major difficulties. This study was undertaken to develop and characterize the usefulness of a novel animal model of APL that is based on an established model of defined exercise in a running wheel by Wistar rats that have been subjected to intracranial self-stimulation (ICSS).

METHODS

Cemented tibial hemiarthroplasties were implanted into the left knees of 7 male Wistar rats. After 2 weeks, exercise in a running wheel was started in all rats, with a running-load of 2 hours/day for 5 days/week. Six months postoperatively, the knee joints were removed, decalcified, and embedded in paraffin. Histologic evaluation on hematoxylin and eosin-stained sections was performed to investigate the development of a SLIM and the presence of cement debris particles. To characterize the SLIM on a molecular level and investigate growth-regulating factors, the expression of transforming growth factor beta (TGFbeta) and the anti-apoptotic molecule Bcl-2 was analyzed by immunohistochemistry.

RESULTS

Although the prostheses appeared mechanically stable after 6 months, the development of SLIM with areas of bone resorption was seen in all samples. Resembling human SLIM, these membranes consisted of loose fibrous tissue, with cement debris particles located particularly at sites originally attached to the prostheses. Immunohistochemistry studies revealed the expression of TGFbeta and Bcl-2 in all specimens. Interestingly, staining for TGFbeta and Bcl-2 was restricted to areas where the SLIM were attached to bone. In contrast, there was only negligible expression of both proteins at sites adjacent to the prostheses.

CONCLUSION

Our findings demonstrate that the ICSS Wistar rat model constitutes a feasible tool for studying early stages of APL, and specifically the effect of defined running exercise on SLIM formation. The results further suggest that both cellular proliferation, as stimulated by TGFbeta, and altered apoptosis contribute to early stages of SLIM formation. The expression patterns of TGFbeta and Bcl-2 indicate that the growth of the SLIM is initiated and promoted from the bone rather than from the prosthesis.

[Recurrent luxations after arthroscopic refixation of the labrum using suture anchors in traumatic ventral shoulder luxation]

OBJECTIVE

Recurrence rates after arthroscopic labral reconstruction for anterior shoulder instability are still higher than after open procedures. Therefore, proper selection of patients becomes increasingly important. The aim of this study was to investigate factors influencing recurrence rates after arthroscopic labral repair with suture anchors.

PATIENTS AND METHODS

We examined 53 patients (43 male, 10 female) with traumatic anterior shoulder dislocations, who were treated with arthroscopic labral repair using Fastak-Suture anchors between 1995 and 1996. The average follow-up time was 18 (12-30) months. The mean age of the patients at the time of operation was 27 (15-44) years.

RESULTS

Postoperatively, 11 patients (20.7%) reported on redislocations. Recurrence rates increased significantly in patients with more than 4 preoperative dislocations and in patients with bony Bankart lesions. In patients without redislocations, the mean Rowe score improved from 65.9 (SD +/- 12.3) preoperatively to 88.6 (SD +/- 12.5) at follow-up. Thus, there were 24 excellent, 9 good and 6 fair results, while in 3 patients with persisting signs of shoulder instability results had to be estimated as poor. Deficits in the range of motion of more than 15 degrees were seen in 7 patients with predominant affection of the external rotation.

CONCLUSION

Frequent preoperative dislocations and bony Bankart lesions contribute substantially to high recurrence rates after arthroscopic labral repair. Therefore, in these cases open procedures should be preferred.

Radiographic findings in osteoarthritis of the knee joint are not correlated with cartilage histomorphology or immunohistochemistry

The purpose of this study was to investigate whether radiographic joint space narrowing (JSN) of the lateral knee compartment predicts the histomorphological or immunhistochemical grading in cases of osteoarthritis of the knee joint. The lateral joint space was measured on weight-bearing radiographs. Femoral osteochondral plugs of 29 patients undergoing total knee replacement were obtained from lateral condyles. All these patients had severe osteoarthritis of the medial compartment, with the lateral compartment showing different stages of osteoarthritis. The specimens were histomorphologically evaluated with the Mankin score, and the expression of the cartilage-degrading enzymes MMP1 and MMP3 was measured. There was no correlation between the joint space and histomorphological or immunohistochemical data, whereas the enzyme expression was correlated with histomorphological grading. We conclude that radiographic assessment alone is not sufficient to evaluate the cartilage damage of the lateral condyle.

[Calcifications after operations of the subacromial space]

OBJECTIVE

Although there are several studies on the development of periarticular calcifications after different operation procedures of the joints, such calcifications have only seldomly been described in connection with operations in the subacromial space. Therefore, the present study was aimed at investigating the incidence of periarticular calcifications after operations in the subacromial space and to assess their clinical relevance.

PATIENTS AND METHODS

In a retrospective study we examined 152 patients (51 female, 101 male) who had been operated on for primary shoulder impingement by open or arthroscopic procedures. The average follow-up time was 32.5 months. The assessment of the outcome of the treatment was performed using the criteria of the Constant score, different shoulder tests, a visual-analog scale for the evaluation of pain, and by evaluation of radiographs.

RESULTS

Our study revealed good clinical results in the operative treatment of different stages of primary shoulder impingement and thus confirmed the results of similar studies before. However, in 25.6% of all patients we found periarticular calcifications. Hereby, calcifications occurred significantly more often after open procedures (56.8%) than after arthroscopic procedures (12.9%). There was non correlation between the occurrence of such calcifications and the stage of the disease. Moreover, comparison of the clinical results and the Constant scores at follow-up did not reveal any differences between patients with and without periarticular calcifications.

CONCLUSION

Our study shows that the presence of periarticular calcifications after operations in the subacromial space is not necessarily associated with clinical symptoms. Therefore, routine prophylactic measurements against such calcifications are not justified.

[Comparison of 2 surgical techniques in isolated supraspinatus rupture. A matched-pair study]

The comparison of results after open surgery methods in the repair of rotator cuff ruptures needs homogen patient groups. We compared 34 patients in 2 groups who were treated with open surgery for isolated ruptures of the supraspinatus muscles (lesion type III). Patients in group I were treated with transosseous suture refixation of the supraspinatus, in group II suture anchors (type: Corkscrew) were used. Both groups were age and gender paired. Preoperatively, all patients had the same clinical status. For the evaluation of the clinical results at follow-up we used the Constant-Score. In addition, strength and pain measurement and oblique X-rays of the shoulder were performed. The follow-up time was 18 months. In all patients, the mean Constant-Score improved significantly with increase in muscle strength and marked pain reduction. Significant differences between both groups could not be observed. The mean time of surgery in group II (suture anchor) was significantly lower than in group I. In conclusion, with the anchor techniques the same good results can be achieved as with bone refixation. The shortening of the surgery time should, however, be seen in relation to the higher costs with this technique.

[Functional changes in the quadriceps femoris muscle in patients with varus gonarthrosis]

In osteoarthritis (OA) of the knee, arthrogenous muscle inhibition (AMI) is considered to be one of the reasons of quadricep muscle weakness. Its influence on functional impairment such as gait alterations, however, still remains unclear. Fourty-seven patients with knee OA (mean age 64 +/- 5.2 years, 36 women, 11 men) and 47 age- and gender-matched healthy controls were investigated for voluntary activation (VA) and maximum voluntary contraction (MVC) of the quadricep muscle. In addition, these two parameters of AMI have been correlated with the extent of gait alterations. Measurement of VA and MVC were performed by a twitch interpolation technique; for gait analysis an optoelectronic motion analysis system (ELITE, Italy) was used. Quadricep MVC and VA were significantly lower in OA than in control knees. Moreover, in addition to reduced walking velocity and step cadence, gait analysis revealed significantly lower stance phase re-extension angles in OA patients (mean 2.7 degrees +/- 2.6) than in control knees (mean 10.7 degrees +/- 4.9). Hereby, in OA knees there was a significant correlation between MVC and VA deficits and the reduction of re-extension angles. The work shows that knee OA is characterized by severe alterations of the quadricep motor function due to arthrogenous muscle inhibition. Hereby, quadricep AMI represents one major reason for functional impairment in knee OA.