Norbert P. Suedkamp

COMPARISON OF MESENCHYMAL STEM CELLS FROM BONE MARROW AND ADIPOSE TISSUE FOR BONE REGENERATION IN A CRITICAL SIZE DEFECT OF THE SHEEP TIBIA AND THE INFLUENCE OF PLATELET-RICH PLASMA

Aim of the present study was to compare the osteogenic potential of bone marrow derived mesenchymal stem cells (BMSC) and adipose-tissue derived stem cells (ASC) and to evaluate the influence of platelet-rich plasma (PRP) on the osteogenic capacity of ASC in a large animal model. Ovine BMSC (BMSC-group) and ASC (ASC-group) were seeded on mineralized collagen sponges and implanted into a critical size defect of the sheep tibia (n=5 each). In an additional group, platelet-rich plasma (PRP) was used in combination with ASC (PRP-group). Unloaded mineralized collagen (EMPTY-group) served as control (n=5 each). Radiographic evaluation was performed every 2 weeks, after 26 weeks histological analysis was performed. Radiographic evaluation revealed a significantly higher amount of newly formed bone in the BMSC-group compared to the ASC-group at week 10 and compared to EMPTY-group from week 12 (all p<0.05). A superiority on radiographic level concerning bone formation of the PRP-group versus the empty control group was found (p<0.05), but not for the ASC-group. Histological analysis confirmed radiographic evaluation finding analogous significances. In conclusion, ASC seem to be inferior to BMSC in terms of their osteogenic potential but that can partially be compensated by the addition of PRP.

Characteristic Complications After Autologous Chondrocyte Implantation for Cartilage Defects of the Knee Joint

Background Although autologous chondrocyte implantation (ACI) is a well-established therapy for the treatment of isolated cartilage defects of the knee joint, little is known about typical complications and their treatment after ACI. Hypothesis Unsatisfactory outcome after ACI is associated with technique-related typical complications. Study Design Case series; Level of evidence, 4. Methods A total of 309 consecutive patients with 349 ACI procedures of the knee joint were analyzed. Three different ACI techniques were used: periosteum-covered ACI in 52 cases (14.9%), Chondrogide (Geistlich Biomaterials, Wolhusen, Switzerland) membrane-covered ACI in 215 cases (61.6%), and a 3-dimensional matrix-associated ACI (BioSeed-C, Biotissue Technologies, Freiburg, Germany) in 82 cases (23.5%). In 52 patients, revision surgery was performed for persistent clinical problems. These patients were analyzed for defect size and location, technique of ACI, and intraoperative findings during revision surgery. The mean time of follow-up for patients after ACI was 4.5 years (standard deviation, ±1.5). Results Four typical major complications were identified: hypertrophy of the transplant, disturbed fusion of the regenerative cartilage and the healthy surrounding cartilage, insufficient regenerative cartilage, and delamination. These diagnoses covered a total of 88.5% of the patients who underwent revision surgery. The overall complication rate was highest in the group of patients treated with periosteum-covered ACI (P = .008). The incidence of symptomatic hypertrophy was 5.2% for all techniques and defect locations; the highest incidence was in patients treated with periosteum-covered ACI (15.4%) (P = .001). The incidence of disturbed fusion was highest in the Chondrogide-covered ACI (3.7%) and the matrix-associated ACI group (4.8%). Concerning the incidence of complications by defect location, there was a tendency for increased complications in patellar defects (P = .095). Within the patellar defects group, no correlation was found for the occurrence of delamination, insufficient regeneration, and disturbed fusion. As a statistical trend, an increased rate of hypertrophy was found for patellar defects (P = .091). Conclusion A major proportion of complications after ACI can be summarized by 4 major diagnoses (symptomatic hypertrophy, disturbed fusion, delamination, and graft failure). Among those, the overall complication rate and incidence of hypertrophy of the transplant were higher for periosteum-covered ACI. Furthermore, an increased rate of symptomatic hypertrophy was found for patellar defects. Therapeutic concepts need to be developed to treat these typical complications of ACI.

Two-Year Results of Open-Wedge High Tibial Osteotomy With Fixation by Medial Plate Fixator for Medial Compartment Arthritis With Varus Malalignment of the Knee

PURPOSE The purpose of our study was to evaluate the complications, technique-related risks, and the clinical course of patients treated with high tibial osteotomy (HTO) for medial arthritis of the knee with varus malalignment. METHODS Forty-three of 46 consecutive patients (follow-up, 93.5%) treated with HTO using the TomoFix implant (Synthes, Solothurn, Switzerland) were followed-up for 24 months. Radiographic and clinical data were collected preoperatively as well as 6, 12, and 24 months after surgery using standard instruments (Lysholm and subjective International Knee Documentation Committee score). RESULTS Excellent and good results were achieved in 67.5% of patients. Thirty-seven patients (86.0%) reported clinical improvement at 24 months compared to preoperative status. Evaluation of the clinical course following HTO revealed a significant increase in function after 12 (P < .01) and 24 (P < .01), but not at 6 months (P = .336) after surgery. A further increase was found between 12 and 24 months (P = .017); 67.5% of the study population returned to their predisease sports activity level at 24 months after surgery. Except for 1 case of intra-articular fracture, no severe intraoperative complications were found. One case of nonunion that demanded additional surgery was observed. CONCLUSIONS HTO with an open-wedge technique using the TomoFix implant seems to be a safe and efficient procedure. Our data show that postoperative recovery is long, with a majority of patients not reaching a functional end-point by 6 or 12 months. In many patients, further improvement was found after 12 months, which might be related to a removal of the implant. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Bone debris: dead matter or vital osteoblasts.

BACKGROUND Mechanical manipulation, pressure, and temperature increase can induce bone necrosis during intramedullary reaming. METHODS In this study, the bone debris obtained after reaming 18 sheep tibiae was analyzed to investigate its vitality by measuring alkaline phosphatase activity. Two different reamer designs were used for the project. Bone cells were first cultivated in a specific growth medium, counted 3 weeks after the reaming procedure, and then cultivated for another 5 weeks. RESULTS At the end of the project, qualitative evaluation showed positive alkaline phosphatase activity in most of the cases, and quantitative evaluation also showed enzyme activity. The positive alkaline phosphatase results were independent of the reamer sizes and reamer design. No significant results were obtained from a comparison of different reamer sizes and designs. This indicates that osteoblasts survive after correctly performed reaming. CONCLUSION The results prove the vitality of the bone debris and confirm clinical observations.

Prognostic factors in nonoperative therapy for chronic symptomatic calcific tendinitis of the shoulder

OBJECTIVE To define prognostic factors in chronically symptomatic patients with calcific tendinitis of the shoulder. METHODS We evaluated 420 patients (488 shoulders) in the context of a prospective cohort study. Epidemiologic data were assessed. The radiographic and sonographic appearance of the calcific deposits was classified. The mean period of nonoperative therapy was 4.4 years (range 0.5-13.7 years). After referral to our institution, standardized nonoperative therapy was continued for a minimum of 3 months. Failure of nonoperative therapy was defined as the persistence of symptomatic calcific tendinitis of the shoulder after a minimum of 6 months. Prognostic factors (determined at P < 0.05 by chi-square test) were analyzed by logistic regression. RESULTS Of the 420 patients, 269 (64%) were women, 151 (36%) were men. The mean age of the patients was 51.3 years (range 28-84 years). Occurrence of calcific tendinitis of the shoulder was unilateral in 84% and bilateral in 16%. Gärtner type I calcific deposits were found in 37%, type II in 32%, and type III in 31%. Failure of nonoperative therapy was observed in 114 patients (27%). Negative prognostic factors were bilateral occurrence of calcific tendinitis of the shoulder, localization to the anterior portion of the acromion, medial (subacromial) extension, and high volume of the calcific deposit. Positive prognostic factors were a Gärtner type III deposit and a lack of sonographic sound extinction of the calcific deposit. CONCLUSION Our findings demonstrate the existence of prognostic factors in the nonoperative treatment of chronic symptomatic calcific tendinitis of the shoulder. Guidelines for optimal treatment can be implemented according to these factors to avoid a long-term symptomatic disease course.

Proximal Humeral Fracture Treatment in Adults

Most proximal humeral fractures affect elderly patients and can be treated nonoperatively with good functional outcomes.The treatment of displaced three and four-part fractures remains controversial and depends on a variety of underlying factors related to the patient (e.g., comorbidity, functional demand), the fracture (e.g., osteoporosis), and the surgeon (e.g., experience).Throughout the literature, open reduction and locking plate osteosynthesis is associated with considerable complication rates, particularly in the presence of osteoporosis.Low local bone mineral density, humeral head ischemia, residual varus displacement, insufficient restoration of the medial column, and nonanatomic reduction promote failure of fixation and impair functional outcome.The outcome of hemiarthroplasty is closely related to tuberosity healing in an anatomic position to enable the restoration of rotator cuff function. Reverse shoulder arthroplasty may provide satisfactory shoulder function in geriatric patients with preexisting rotator cuff dysfunction or after the failure of first-line treatment.

Stabilization of the long head of the biceps tendon in the context of early repair of traumatic subscapularis tendon tears.

BACKGROUND Tears of the subscapularis tendon commonly are associated with instability of the long head of the biceps tendon. Standard surgical treatment includes tenodesis or tenotomy of the biceps tendon. However, chronic discomfort from spasms and cosmetic disadvantages have been reported following both procedures, while the potential for functional impairments remains controversial. We investigated the outcome of stabilization of the long head of the biceps tendon in the context of early repair of traumatic tears of the subscapularis tendon. METHODS We performed stabilization of an unstable, structurally intact long head of the biceps tendon in twenty-one patients in the acute phase after a traumatic tear of the subscapularis tendon. The average period from the injury to the surgery was 6.2 weeks. Open tendon stabilization and subscapularis reconstruction were performed with transosseous sutures. The follow-up consisted of clinical examination (with determination of the absolute, age and gender-related, and individual relative Constant scores; clinical evaluation of the long head of the biceps; and subjective determination of shoulder function) and dynamic ultrasound examination. RESULTS The average follow-up period was 28.4 months. The mean absolute Constant score increased from 26.3 points preoperatively to 79.3 points postoperatively (p < 0.01). The mean age and gender-related Constant score improved from 28.0% to 87.0% (p < 0.01). Seven patients showed clinical symptoms consistent with mild biceps tendinopathy. Using dynamic ultrasound examination, we found two cases of recurrent instability (medial subluxation) of the long head of the biceps tendon. Secondary rupture of the long head of the biceps tendon occurred in one patient, twenty-six months after the surgery. CONCLUSIONS The functional outcomes of stabilization of the long head of the biceps tendon in the context of early repair of a traumatic tear of the subscapularis tendon were comparable with the results of tenodesis or tenotomy reported in previous studies. The cosmetic results were superior, and chronic discomfort from spasms was not observed. Stabilization of the tendon of the long head of the biceps can be recommended as a treatment option for selected patients and should be discussed as an alternative to tenodesis or tenotomy, particularly in a young patient.

Angioembolization for pelvic hemorrhage control: results from the German pelvic injury register.

BACKGROUND Hemorrhage from pelvic vessels is a potentially lethal complication of pelvic fractures. There is ongoing controversy on the ideal treatment strategy for patients with pelvic hemorrhage. The aim of the study was to analyze the role of angiography and subsequent embolization in patients with pelvic fractures and computed tomography scan-proven vascular injuries. METHODS The data from the prospective multicenter German pelvic injury registry were analyzed. Of 5,040 patients with pelvic fractures, 152 patients with associated vascular injuries were identified. Patients undergoing angioembolization (n = 17) were compared with those undergoing conventional measures for hemorrhage control (n = 135) with regard to demographic and physiologic parameters, fracture type distribution, and treatment measures. Outcome measures were mortality, requirement for blood transfusions, complications, and hospital length of stay. RESULTS Embolization and nonembolization groups were comparable with regard to age, sex, Injury Severity Score, Hannover Polytrauma Score, initial hemoglobin levels, blood pressure, fracture distribution, and conventional measures. Blood transfusion requirement was significantly prolonged in the embolization group. This resulted in a higher adult respiratory distress syndrome incidence and a tendency toward increased multiple organ failure rate in this group. There was no significant difference in overall mortality rate when compared with the nonembolization group (17.6% vs. 32.6%, respectively; p = 0.27). None of the patients undergoing embolization died from exsanguination when compared with 20.6% in the nonembolization group (p = 0.038). CONCLUSION Angioembolization alongside with conventional measures is an effective complementary means for hemorrhage control in patients sustaining pelvic fracture-related vascular lesions. It might prove even more effective when performed early enough to avoid prolonged blood transfusion requirement. Further studies without the mentioned limitations of the study are desired. LEVEL OF EVIDENCE Therapeutic study, level IV.

Rotator Cuff Preservation in Arthroscopic Treatment of Calcific Tendinitis

PURPOSE We sought to evaluate (1) clinical and radiologic results after arthroscopic calcific deposit (CD) removal and (2) the relevance of remnant calcifications (RCs). METHODS The study included 102 patients undergoing arthroscopic CD removal, preserving integrity of the rotator cuff. Postoperatively, we divided patients into 2 groups according to the extent of CD removal achieved. Group 1 consisted of patients with complete CD removal. Group 2 included patients showing minor RCs. Ninety-three patients (99 shoulders) completed follow-up. The mean patient age was 50.6 years (31 to 68 years), and the mean follow-up period was 37.3 months (24 to 83 months). We obtained anteroposterior (AP) and outlet radiographs before surgery, postoperatively, and at follow-up. We used the absolute and age- and sex-related Constant scores (CSabs, CSrel) as outcome measures. We compared both groups statistically (Mann-Whitney U test; P < .05). RESULTS Complete CD removal was achieved in 82 of 99 (82.8%) shoulders (group 1). Postoperatively, minor RCs were found in 17 of 99 (17.2%) shoulders (group 2), an average of 58.6% (± 26.2) of the mean preoperative size. All RCs showed complete (14 of 17) or virtually complete (3 of 17) resolution at follow-up. Overall mean CSabs and CSrel were 88.8 points (± 10.4) and 99.0% (± 3.7), respectively. Mean values of CSabs and CSrel in group 1 (89.5 points ± 9.5 and 99.1% ± 3.7, respectively) and group 2 (86.1 points ± 12.9 and 98.7% ± 4.2, respectively) did not differ. CONCLUSIONS Arthroscopic CD removal, preserving integrity of the rotator cuff yielded good to excellent results in 90% of patients and avoided iatrogenic tendon defects in all patients. Minor RCs did not impair clinical outcome and spontaneously resolved at follow-up. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Reliability of leg alignment using the OrthoPilot system depends on knee position: a cadaveric study

Despite the increase in clinical use of navigation systems in total knee arthroplasty, few studies have focused on the reproducibility of these systems. The aim of the present study was to assess the influence of knee position and observer experience on intra- and inter-observer agreement in limb alignment assessment with the OrthoPilot system. Limb alignment in the coronal plane and extension range of the knee were assessed in four embalmed cadaveric specimens by five independent observers and measurements were repeated four times to determine intra- and inter-observer agreement, expressed as intraclass correlation coefficients (ICCs). Additionally, navigation results were compared against figures from conventional measurement of leg alignment (ground truth). Intra- and inter-observer agreements were excellent for assessing the extension range (ICC, 0.97 and 0.95) and the coronal femuro-tibial axis in knee extension (ICC, 0.92 and 0.88) but were generally worse in knee flexion (ICC, 0.62 and 0.55). There was an increased tendency of intraobserver errors in observers with less clinical experience. Mean correlation with conventional measurements was fair (Spearman’s rho 0.61). The OrthoPilot system showed excellent reproducibility for assessment of extension range and coronal limb alignment. However, assessments of coronal limb alignment in flexion were prone to error and caution should be taken when relying on these measurements.