[Effect of cyclical stretch on matrix synthesis of human patellar tendon cells]

The significance of mobilization and loading for healing ligaments and tendons is generally accepted today. Local deformation of cells thereby represents the key stimulus for the cellular response. Less is known, however, about the effects of cyclic strain on the cellular and molecular level. The aim of the in vitro investigation was to determine the effect of cyclic mechanical strain on collagen type I and III and on fibronectin formation in human patellar tendon derived fibroblasts. Human patellar tendon derived fibroblasts from 5 donors (mean age 29.2 years) were cultured under standard conditions. Monolayers of subconfluently grown 3rd passage cells were stretched in rectangular silicone dishes with cyclic movement along their longitudinal axes. Cyclic strain (5%, 1 Hz) was applied for 30 min and 60 min, respectively. Carboxyterminal procollagen type I propeptide (P-I-CP) and aminoterminal procollagen type III propeptide (P-III-NP) release was measured by a radio-immunoassay 6 h and 12 h after stretching. The release of fibronectin was measured by nephelometry following immunoreaction with a specific antiserum. Cells from each donor without any cyclic stretching served as controls. Compared with the controls, only cyclic stretching for 60 min resulted in a significantly increased release of P-I-CP and fibronectin after 6 h. The release of P-III-NP was significantly increased 12 h after 30 min of cyclic stretching as well as 6 h and 12 h after 60 min of cyclic stretching, respectively. We conclude that cyclic stretching causes a time-dependent, differential regulation of formation of fibronectin and collagen type I and III. This may effect the quality and thus the mechanical properties of healing tendon and ligament tissues. In order to improve current treatment protocols and to enlarge our knowledge of tissue healing, it is necessary to understand the cellular response to cyclic strain.

[Minimally invasive screw fixation of the intracapsular femoral neck fracture in elderly patients]

INTRODUCTION

Increasing life expectancy is associated with an increase of geriatric fractures such as intracapsular femoral neck fractures. Their treatment by arthroplasty imposes a significant burden on our health care system.

METHODS

In an open clinical study we investigated the complication rate of a less expensive and less invasive, femoral head saving operative procedure. Between June 1997 and June 2000, 205 intracapsular femoral neck fractures of elderly patients (mean age 78.1 +/- 11.8 years) were fixed with cannulated screws.

RESULTS

Seventy-seven percent were displaced fractures and 15.6% were impacted Garden I fractures. Reoperation after internal fixation occurred in 38 patients. The most frequent cause of reoperation was secondary arthroplasty due to redisplacement (14x), femoral head necrosis (10x) and non-union (7x). Implant removal (4x), wound hematoma (1x) and femoral head penetration by screws (2x) were other causes for reoperation.

CONCLUSION

Less invasive cannulated screw fixation of intracapsular femoral neck fractures should be considered as a treatment option, because it is a smaller and less expensive operation than prosthetic replacement. Adequate reduction and screw placement, however, are a prerequisite for successful outcome.

Cyclic mechanical stretching modulates secretion pattern of growth factors in human tendon fibroblasts

The objective of the study was to investigate whether the response profile of the growth factor of human tendon fibroblasts could be beneficially influenced through the application of mechanical stretch. It was considered that this would elucidate structural and functional problems, often seen after tendon and ligament healing. The secretion pattern of transforming growth factor-beta (TGF-beta), platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) was determined in mechanically stretched fibroblasts and compared to non-stretched controls. Human tendon fibroblasts were experimentally stretched for 15 and 60 mm at a frequency of 1 Hz and an amplitude of 5%. The secretion of TGF-beta PDGF and bFGF was measured by enzyme-linked immuno-sorbent assay. All the growth factors investigated were indeed secreted by human tendon fibroblasts both in stretched cells and controls. Mechanical stretch increased the secretion pattern of the growth factors. The increased concentrations of TGF-beta bFGF and PDGF after cyclical mechanical stretching may have a positive influence on tendon and ligament healing through stimulation of cell proliferation, differentiation and matrix formation.

Arthrofibrosis is the result of a T cell mediated immune response

It is thought that an excessive fibrotic healing response with diffuse intra-articular scarring leads to arthrofibrosis after trauma and surgery around joints. To clarify the specific cellular mechanism of arthrofibrosis during arthrolysis we took fibrotic tissue samples from 18 patients at varying periods after knee trauma or surgery. Sections were stained with hematoxylin and eosin to study the overall histopathological changes. Major histocompatibility complex (MHC) class II expressing cells as well as CD3, CD4, CD25, CD28, CD68, CD80, and CD83 positive cells were localized immunohistologically. The results demonstrated synovial hyperplasia with fibrotic enlargement of the subintima and infiltration of inflammatory cells. The number of MHC class II expressing cells was increased. Mainly, intimal macrophages and dendritic cells showed positive immunostaining for MHC class II antigens. In the subintima moderate infiltration of T cells including activated T cells (CD25), CD4+ T helper (Th) cells and Th1 and Th2 subsets was detected. There was a slight polarization of the Th1/Th2 balance towards Th1 differentiation. Positive immunostaining for CD80/CD28 indicated the costimulatory signal for T cell activation and clonal expansion. These findings strongly support an immune response as the cause of capsulitis leading to formation of diffuse scar tissue within the knee joint. Based on our immunohistological study we conclude that a T cell mediated immune response plays a crucial role in the mechanism of arthrofibrosis.

Cyclic mechanical stretching enhances secretion of Interleukin 6 in human tendon fibroblasts

Accelerated rehabilitation after tendon and ligament injuries is widely accepted to avoid adverse effects of immobilization. However, progressive rehabilitation may also lead to an excessive inflammatory soft tissue response. To investigate the amount of loading necessary to accelerate the healing process without causing damage to the healing tissue, we experimentally stretched human tendon fibroblasts of healthy tendons 15 and 60 min with 1 Hz and an elongation of 5% and measured the secretion of interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-alpha), transforming growth factor beta1 (TGF-beta1), platelet-derived growth factor (PDGF), and fibroblast growth factor basic (bFGF). Secretion of IL-6 was significantly induced by 15 min of cyclic biaxial mechanical stretching after 4 and 8 h observation time and by 60 min stretching and 2 h observation time. The growth factors TGF-beta1, bFGF, and PDGF were secreted by human tendon fibroblasts both in stretched cells and controls; however, no increases were related to mechanical stretching. There was no measurable secretion of TNF-alpha in human tendon fibroblasts. These findings suggest that the inflammatory reaction often seen during physiotherapy after tendon and ligament injuries is caused in part by secretion of IL-6 from the stretched human tendon fibroblasts. IL-6 may cause exaggerated proliferation of fibroblasts and synovial cells as seen in rheumatoid arthritis and arthrofibrosis. However, physiological proliferative reactions leading to repair of injured tissue are also possible. IL-6 measured in the synovial fluid may be an important predictor for monitoring and improving therapeutic strategies in terms of tendon/ligament healing.

[Outcome analysis after open reconstruction of rotator cuff ruptures. A comparative assessment of recent evaluation procedures]

Outcome evaluation is becoming increasingly important for reconstructive surgery in musculoskeletal diseases. In addition to established shoulder-scores, new outcome-scores are being developed to cover all effects caused by a disease or intervention. Three validated, self-administered shoulder questionnaires were applied prospectively in 23 otherwise healthy patients suffering from rotator cuff deficiency. These were correlated to the Constant-Murley Shoulder Score and to a visual analogue scale for satisfaction. 7 women and 16 men with combined tears of supraspinatus and infraspinatus (mean age 55.3 +/- 10.5, r/l: 14/9, FU 57.8 +/- 15.7 weeks) were gathered prospectively and evaluated pre- and postoperatively with the American Shoulder and Elbow Surgeons Shoulder Index (ASES), the Simple Shoulder Test (SST) and the Disabilities of the Arm, Shoulder and Hand Module (DASH questionnaire). In addition, a visual analogue scale for satisfaction was employed. All four scores as well as the visual analogue scale revealed improvement at a statistically significant level (paired, two-tailed t-test, P < 0.01) after surgery. All questionnaires had a significant correlation with the Constant-Murley Shoulder Score (Pearson's correlation coefficient: ASES: r = 0.871, P < 0.01; DASH: r = -0.758, P = < 0.01; SST: r = 0.494, P < 0.05). All were easy to apply and provided a reliable, postoperative evaluation of shoulder function. The SST was easy to apply, however compound outcome analysis was only possible with the ASES Shoulder Index and the DASH questionnaire. The DASH scale was the most complex evaluation instrument. The Constant-Murley Shoulder Score comprises a physical examination which is advantageous but must be carried out in the clinic. For postoperative assessment, without the patient having to return to the clinic, the ASES Shoulder Index is preferred as it correlates well with the Constant-Murley Shoulder Score (r = 0.871) and the visual analogue scale for satisfaction (r = 0.762).

Akute AC-Gelenksprengung - operative oder konservative Therapie?

42 patients with complete acromioclavicular dislocation treated operatively and 38 patients managed non-operatively were examined retrospectively with a mean follow-up of 6.3 +/- 2.5 years. The dislocations in both groups included type III and type V injuries according to the Rockwood-classification. The operative technique was suturing of the tom ligaments and stabilization of the acromioclavicular joint using resorbable coracoclavicular PDS-banding. In non-operative treatment, early physiotherapy accepting the deformity was performed in most of the patients. The clinical results using the UCLA- and the Constant-Murley score as well as evaluation of pain, function and strength were similar in both groups. Those patients suffering from a more severe dislocation type Rockwood V who were treated non-operatively had as good results as those patients with grade III dislocation. Posttraumatic osteoarthritis developed mainly in those patients whose acromioclavicular joint healed in partial dislocation. Non-operative treatment was equal even in less severe dislocations in the subgroup of type Rockwood V injuries. The persisting deformity which must be expected in non-operative treatment did not affect the patient's outcome regarding pain, function and strength of the shoulder.

Outcome analysis following open rotator cuff repair. Early effectiveness validated using four different shoulder assessment scales

Evaluation of upper extremity function after reconstructive surgery is increasingly important both to predict outcome and for the control of cost-effectiveness. Three validated, self-administered shoulder questionnaires were applied prospectively in 23 otherwise healthy patients with rotator cuff deficiency and correlated to the Constant-Murley Shoulder Score and a visual analogue scale for satisfaction. Seven women and 16 men with combined tears of supraspinatus and infraspinatus (mean age 55.3 +/- 10.5 years, r/l: 14/9, follow-up 57.8 +/- 15.7 weeks) were gathered prospectively and evaluated pre- and postoperatively with the American Shoulder and Elbow Surgeons (ASES) Shoulder Index, the Simple Shoulder Test (SST) and the Disabilities of the Arm, Shoulder and Hand Module (DASH questionnaire). Additionally, a visual analogue scale for satisfaction was employed. All four scores and the visual analogue scale revealed improvement at a statistically significant level (P < 0.01) after surgery. All questionnaires showed a significant correlation with the Constant-Murley Shoulder Score (ASES: r = 0.871, P < 0.01; DASH: r = -0.758, P < 0.01, SST: r = 0.494, P < 0.05, Pearson's correlation coefficient). Taken together, all questionnaires were easy to apply, and reliable evaluation of shoulder function was possible with significant correlation to the Constant-Murley Shoulder Score postoperatively. The SST was easy to apply, and compound outcome analysis was possible with the ASES Shoulder Index and DASH questionnaire. The DASH scale was the most complex evaluation instrument. The Constant-Murley Shoulder Score comprises a physical examination, which is advantageous but restricts the application to the office. For postoperative assessment without the patient having to return to the clinic, the ASES Shoulder Index is preferred because of its good correlation to the Constant-Murley Shoulder Score (r = 0.871) and the visual analogue scale for satisfaction (r = 0.762).

Proprioception in anterior cruciate ligament reconstruction. Endoscopic versus open two-tunnel technique. A prospective study

ACL-reconstruction with patellar tendon autograft is a standard procedure which can be performed arthroscopically with a femoral half tunnel drilled from the joint or using the two-tunnel technique with medial miniarthrotomy and additional femoral approach. The arthroscopic procedure with single incision was hypothesized to improve proprioception and to provide earlier rehabilitation. Twenty-nine patients with chronic ACL-deficiency were included in the prospective study. Fifteen patients were operated endoscopically, 14 patients using the two-tunnel technique. Proprioception, Lysholm and Tegner scores as well as stability (KT-1000) were assessed preoperatively, 3 and 6 months postoperatively as well as after 3.9 +/- 0.4 years. A significant deficit of proprioception was assessed in both groups preoperatively. Six months postoperatively, both groups showed a restitution of proprioception near full extension and full flexion of the knee. In the mid-range position, the proprioception could not be restored. At the final examination after 3.9 years, the deficit documented in the mid-range position still persisted. There were no differences in proprioception, clinical results and stability between the arthroscopic and the open technique.

[Proprioception after reconstruction of the anterior cruciate ligament. Endoscopic vs. 2 tunnel technique]

ACL reconstruction with patellar tendon autograft is a standard procedure which can be performed arthroscopically with a femoral half tunnel drilled from the joint or using the two-tunnel technique with medial miniarthrotomy and additional femoral approach. The arthroscopic procedure with single incision was supposed to increase stability and to improve proprioception by earlier rehabilitation. 29 patients with ACL deficiency were included in the study. 15 patients were treated endoscopically, 14 patients by using the two-tunnel technique. Proprioception, Lysholm and Tegner scores as well as stability (KT-1000) were assessed preoperatively, 3 and 6 months postoperatively. A deficit of proprioception was assessed in either group preoperatively, which could be improved after 3 months only in the arthroscopic group. 6 months postoperatively, either group showed a restitution of proprioception near full extension and full flexion of the knee. In the mid range position, the proprioception could not be restored. There were no differences in stability and the Lysholm and Tegner scores between the groups after 6 months postoperatively. The comparison between the patients with acute and chronic instability shows a better proprioception in the acute group in the mid range position 6 months after the reconstruction.

Proprioception after rehabilitation and reconstruction in knees with deficiency of the anterior cruciate ligament: a prospective, longitudinal study

We assessed proprioception in the knee using the angle reproduction test in 20 healthy volunteers, ten patients with acute anterior instability and 20 patients with chronic anterior instability after reconstruction of the anterior cruciate ligament (ACL). In addition, the Lysholm-knee score, ligament laxity and patient satisfaction were determined. Acute trauma causes extensive damage to proprioception which is not restored by rehabilitation alone. Three months after operation, there remained a slight decrease in proprioception compared with the preoperative recordings, but six months after reconstruction, restoration of proprioception was seen near full extension and full flexion. In the mid-range position, proprioception was not restored. At follow-up, 3.7 +/- 0.3 years after reconstruction, there was further improvement of proprioception in the mid-range position. There was no difference between open and arthroscopic techniques. The highest correlation was found between proprioception and patient satisfaction. After reconstruction of the ACL reduced proprioception may explain the poor functional outcome in some patients, despite restoration of mechanical stability.

Proprioception after rehabilitation and reconstruction in knees with deficiency of the anterior cruciate ligament

We assessed proprioception in the knee using the angle reproduction test in 20 healthy volunteers, ten patients with acute anterior instability and 20 patients with chronic anterior instability after reconstruction of the anterior cruciate ligament (ACL). In addition, the Lysholm-knee score, ligament laxity and patient satisfaction were determined.

Acute trauma causes extensive damage to proprioception which is not restored by rehabilitation alone. Three months after operation, there remained a slight decrease in proprioception compared with the preoperative recordings, but six months after reconstruction, restoration of proprioception was seen near full extension and full flexion. In the mid-range position, proprioception was not restored. At follow-up, 3.7 ± 0.3 years after reconstruction, there was further improvement of proprioception in the mid-range position. There was no difference between open and arthroscopic techniques. The highest correlation was found between proprioception and patient satisfaction. After reconstruction of the ACL reduced proprioception may explain the poor functional outcome in some patients, despite restoration of mechanical stability.

[Nonunion of the humeral diaphysis - operative and nonoperative treatment]

Operative treatment of acute humeral shaft fractures represents a major source of nonunions. The analysis of the biomechanical and biological causes of diaphyseal nonunions of the humerus is a prerequisite for the successful treatment of ununited humeral shaft fractures. Biologically active nonunions heal after debridement and correction of deformities with an improvement of mechanical stability, preferably by fixation with a compression plate. In atrophic nonunions, the restoration of the biologic capacity to restore osteogenesis by bone grafting is additionally necessary. The treatment of synovial pseudarthrosis and infected nonunion requires removal of bone and debridement of synovial and infected avascular tissues, respectively. Intramedullary nails to improve mechanical stability and nonoperative treatment with extracorporeal shock waves should only be used in a few special cases which do not have any severe deformities.

The Harris Design-2 total hip replacement fixed with so-called second-generation cementing techniques. A ten to fifteen-year follow-up

We analyzed the clinical results of 195 Harris Design-2 total hip replacements performed with so-called second-generation cementing techniques in 166 consecutive patients who had osteoarthrosis. The mean age of the patients at the time of the replacement was sixty-seven years and nine months (range, thirty-one to eighty-nine years). Forty-eight patients (fifty-four hips) died before the time of the latest follow-up, but the implants were apparently functioning well at the time of death. Three patients (four hips) were lost to follow-up. Five patients (five hips; 3 percent) had a revision because of aseptic loosening of the acetabular or femoral component, or both, that was related to wear-induced osteolysis. The mean Harris hip score for the 131 hips that were available at the latest follow-up examination at a mean of twelve years (range, ten to fifteen years) after the operation was 89 +/- 10 points. On the basis of the Harris hip score, seventy-six hips had an excellent result, thirty-four had a good result, fifteen had a fair result, and six had a poor result at the latest follow-up examination. Radiographically, twelve (9 percent) of the 131 acetabular components and three (2 percent) of the 131 femoral components were probably or definitely loose. At a mean of twelve years, 186 (97 percent) of 191 Harris Design-2 implants were in situ or had been in situ at the time of the patient's death.

Outcome after primary and secondary hemiarthroplasty in elderly patients with fractures of the proximal humerus

Thirty-nine consecutive patients with 3- and 4-part proximal humeral fractures and fracture dislocations were treated with hemiarthroplasty. After an average of 42 months (range 5 to 98 months) of follow-up, 17 women and 8 men (average age 64.5 years) were evaluated with the University of California-Los Angeles (UCLA) scale, the Constant-Murley scale, the Hospital for Special Surgery (HSS) scale, and the visual analogue scale. Fair, good, or excellent results were achieved in 80% of the patients on the UCLA and Visual scales, in 72% of the patients on the HSS scale, and in 44% of the patients on the Constant-Murley scale. The highest correlation was between the HSS score and the Visual analogue score. According to the UCLA and Constant-Murley results, the outcome after early (<4 weeks) humeral head replacement was significantly better than after late (> or =4 weeks) humeral head replacement (UCLA score, P=.02; Constant-Murley score, P=.01). After early hemiarthroplasty active forward flexion was significantly better (P=.035). Thus the decision to perform prosthetic humeral head replacement in elderly patients should be made as early as possible after trauma.

Extension osteotomy in malunited clavicular fractures

The association of a malunited clavicular fracture with a pattern of disability that includes not only pain but also impairment of shoulder function is rare. But in cases where such an association exists, correction of the clavicular deformity should be considered. We report on 4 patients with a malunited fracture of the clavicle after nonoperative treatment. In all 4 patients fracture union had occurred with shortening associated with pain and ipsilateral glenohumeral dysfunction. The deformity was not associated with neurovascular dysfunction. On preoperative radiographs the shortening of the malunited clavicle was between 0.9 and 2.2 cm compared with the contralateral clavicle. all patients underwent an extension osteotomy of the clavicle with interposition of an autogenous iliac crestbone graft secured with a plate and screws. The length of follow-up was 1 to 4 years in 3 cases and 6 weeks in 1 case. The functional outcome was evaluated with the Constant-Murley and University of California-Los Angeles scales. All patients had immediate pain relief after osteotomy and correction of the deformity. Shoulder function rapidly improved and functional outcome was good in 3 of the 4 patients. In cases of shoulder function impairment associated with malunited clavicular fractures, extension osteotomy combined with autogenous bone grafting is likely to produce good results.

Level of physical activity in elderly patients after hemiarthroplasty for three- and four-part fractures of the proximal humerus

We report on 13 physically active patients who performed sports activities at a weekend or recreational level when they suffered a severe proximal humerus fracture or fracture dislocation. All patients were treated using the NEER II hemiarthroplasty, 9 patients within 4 weeks after trauma and 4 patients 2, 5, 10 and 15 months after trauma. At an average follow-up of 50 (range 6-98) months, all patients were evaluated, both by clinical review and radiographs. Patients obtained 69.0 points using the HSS score (Hospital for Special Surgery) for evaluation. Subjectively, 85% of the patients evaluated the result as 'good' or 'excellent' on a visual analogue scale for satisfaction. There was no radiographic evidence of implant loosening. At an average period of 33 (range 16-52) weeks 10 patients started with their physical activities again without a change in their participation level.

[Hemi-arthroplasty--primary or secondary measure for 3- and 4-fragment fractures of the proximal humerus in the elderly?]

Successful treatment of three- and four-part proximal humerus fractures is a therapeutic challenge to the surgeon, particularly in the case of elderly patients. Open reduction and internal fixation have been advocated, but have not consistently produced acceptable results. The results of humeral head replacement as a salvage procedure after non-union or failed open reduction and internal fixation are less predictable. The outcome of hemiarthroplasty (Neer II) performed for three- and four-part proximal humerus fractures in elderly patients was studied. The average patient follow-up was 42.9 months (range 5-98). Eighteen women and eight men with an average age of 64.5 years were evaluated according to the UCLA. Constant-Murley and HSS Score. A Visual Score (0-100 points) was also used. Hemiarthroplasty was performed in 11 patients within 4 weeks of trauma and in 15 patients after 4 weeks. Fair, good, or excellent results were achieved in 80% (UCLA and Visual), 73% (HSS) and 46% (Constant-Murley) of the patients, respectively. Ninety-six percent of the patients reported only slight or no pain. The range of motion was limited in almost all cases. The outcome was not significantly influenced by age, sex and follow-up time. However, there was a significant correlation between the outcome and the length of time between injury and humeral head replacement (r = -0.5). The outcome after early hemiarthroplasty was better than after late humeral head replacement (UCLA: 27.1 +/- 4.6 vs 22.5 +/- 5.6 P = 0.04; Constant-Murley: 65.6 +/- 18.5 vs 47.5 +/- 18.6, P = 0.02; HSS: 74.0 +/- 14.4 vs 63.5 +/- 17.6, P = 0.17). Self-assessment did not differ between these two groups. After early hemiarthroplasty, active forward flexion was significantly better. This study indicates that early humeral head replacement for three- and four-part proximal humerus fractures in elderly patients achieved better functional outcome than delayed humeral head replacement. The decision to perform prosthetic humeral head replacement in these cases should be made as early as possible after trauma.