Microfracture for the treatment of cartilage defects in the knee joint – A golden standard?

The evidence for the effectiveness of the microfracture procedure is largely derived from case series and few randomized trials. Clinical outcomes improve with microfracture for the most part, but in some studies these effects are not sustained. The quality of cartilage repair following microfracture is variable and inconsistent due to unknown reasons. Younger patients have better clinical outcomes and quality of cartilage repair than older patients. When lesion location was shown to affect microfracture outcome, patients with lesions of the femoral condyle have the best clinical improvements and quality of cartilage repair compared with patients who had lesions in other areas. Patients with smaller lesions have better clinical improvement than patients with larger lesions. The necessity of long postoperative CPM and restricted weight bearing is widely accepted but not completely supported by solid data. Maybe new developments like the scaffold augmented microfracture⁶ will show even more consistent clinical and biological results as well as faster rehabilitation for the treatment of small to medium sized cartilage defects in younger individuals.All in all there is limited evidence that micro fracture should be accepted as gold standard for the treatment of cartilage lesions in the knee joint. There is no study available which compares empty controls or non-surgical treatment/physiotherapy with microfracture. According to the literature there is even evidence for self regeneration of cartilage lesions. The natural history of damaged cartilage seems to be written e.g. by inflammatory processes, genetic predisposition and other factors. Possibly that explains the large variety of the clinical outcome after micro fracture and possibly the standard tools for evaluation of new technologies (randomized controlled trials, case series, etc.) are not sufficient (anymore).Future technologies will be evaluated by big data from international registries for earlier detection of safety issues, for detection of subtle but crucial co-factors for failure and osteoarthritis as well as for lower financial burdens affecting industry and healthcare systems likewise.     

Can CT determine the site of traumatic osteochondral defects in the paediatric knee?

Currently the ability of pre-operative CT imaging to determine the origin of traumatic osteochondral lesions (OCL) in the knee in children is yet to be established. The surgical approach to the knee will to some extent be determined by the origin of the lesion. It is important to directly determine the site of the lesion from pre-operative scanning both to facilitate surgery, to have a better cosmetic result for the patient and have a quicker rehabilitation period. In a tertiary referral centre, from May 2004 to April 2005, eight patients were diagnosed as having an OCL. The initial reporting was done by either a senior registrar or consultant paediatric radiologist. Those children that had an OCL underwent an arthroscopy or definitive open surgery. The exact site of the lesion was then determined and recorded in the operative notes. All the original pre-operative CT scans were given to a senior paediatric radiologist. The consultant on this occasion had no access to operative findings, or original CT reports. CTs reported by the paediatric radiology department are only able to correctly identify the site of origin of the OCL 50% of the time. Recent MR scanning techniques have improved the visualization of OCL. We authors therefore feel that in the future MRI should be used to assess the paediatric knee when an acute OCL is suspected.     

Do meta-analyses reveal time-dependent differences between the clinical outcomes achieved by microfracture and autologous chondrocyte implantation in the treatment of cartilage defects of the knee?

Purpose

To test the hypothesis that autologous chondrocyte implantation (ACI) has a better treatment effect than microfracture (MF), and increasing superiority over the years, when performed under similar patient-specific and defect-specific conditions.

Methods

We scanned four electronic databases for controlled clinical trials or controlled prospective observational studies. We conducted random-effects meta-analyses of equivalent data using standardized mean differences as the outcome measure of choice at 1, 2, and 5-year follow-up. We assessed heterogeneity with the I ² index and publication bias with funnel plots and Kendall’s tests.

Results

Our literature search revealed six study populations (nine papers) which satisfied our eligibility criteria. Overall, 399 patients aged between 16 and 60 years with 1–10 cm² chondral defects were available. The MF and the ACI study groups were well matched regarding patient baseline characteristics. For all papers, microfracture was performed according to Steadman, whereas three generations of ACI were applied. When all were combined, non-significant superiority of ACI over MF was revealed; surprisingly, this superiority decreased over the years. However, our meta-analyses combining solely second and third-generation ACI revealed significant standardized differences, becoming smaller over the years, but always representing a large effect. Nevertheless, our approximate estimate of the difference between the treatment effects provoked by second and third-generation ACI and by MF is not indicative of clinically relevant superiority of ACI over MF at 5-year follow-up.

Conclusions

Both series of meta-analyses (combining either all ACI modifications or solely the second and third generations of ACI) suggest that the treatment effects resulting from ACI and MF converge over the years.     

Repairing articular cartilage defects with tissueengineering cartilage in rabbits

Objective: To investigate the effect of cancellous bone matrix gelatin ( BMG ) engineered with allogeneic chondrocytes in repairing articular cartilage defects in rabbits. Methods: Chondrocytes were seeded onto three-dimensional cancellous BMG and cultured in vitro for 12 days to prepare BMG-chondrocyte complexes. Under anesthesia with 2.5% pentobarbital sodium (1ml/kg body weight), articular cartilage defects were made on the right knee joints of 38 healthy New Zealand white rabbits (regardless of sex, aged 4-5 months and weighing 2. 5-3 kg) and the defects were then treated with 2. 5% trypsin. Then BMG-chondrocyte complex ( Group A, n = 18 ), BMG (Group B, n = 10), and nothing (Group C, n = 10) were implanted into the cartilage defects, respectively. The repairing effects were assessed by macroscopic, histologic, transmission electron microscopic ( TEM ) observation, immunohistochemical examination and in situ hybridization detection, respectively, at 2, 4, 8, 12 and 24 weeks after operation. Results: Cancellous BMG was degraded within 8 weeks after operation. In Group A, lymphocyte infiltration was observed around the graft. At 24 weeks after operation, the cartilage defects were repaired by cartilage tissues and the articular cartilage and subchondral bone were soundly healed. Proteoglycan and type II collagen were detected in the matrix of the repaired tissues by Safranin-O staining and immunohistochemical staining, respectively. In situ hybridization proved gene expression of type II collagen in the cytoplasm of chondrocytes in the repaired tissues. TEM observation showed that chondrocytes and cartilage matrix in repaired tissues were almost same as those in the normal articular cartilage. In Group B, the defects were repaired by cartilage-fibrous tissues. In Group C, the defects were repaired only by fibrous tissues. Conclusions: Cancellous BMG can be regarded as the natural cell scaffolds for cartilage tissue engineering. Articular cartilage defects can be repaired by cancellous BMG engineered with allogeneic chondrocytes. The nature of repaired tissues is closest to the normal cartilage. Local administration of trypsin can promote the adherence of repaired tissues to host tissues. Transplantation of allogeneic chondrocytes has immunogenicity, but the immune reaction is weak.     

Is neoadjuvant therapy the answer to adenocarcinoma of the esophagus?

The conflicting results of randomized studies have led to confusion over the proper management of patients with esophageal adenocarcinoma. Although there is no firm evidence that neoadjuvant chemoradiation improves survival, because of the shortcomings of these trials, this method of treatment is practiced at many centers. Without the results of another multiinstitutional randomized trial, the true answer may never be known.     

MRI vs. arthroscopy in the diagnosis of cartilage lesions in the knee. Can MRI take place of arthroscopy?

INTRODUCTION: The accuracy of magnet resonance imaging in diagnosing cartilage lesions is discussed controversially. The sensitivity of this examination ranges from 15 % to 96 %. Clinical evidence demonstrates that cartilage lesions, diagnosed by MRI, were not confirmed in arthroscopy. The purpose of this prospective study was to analyse the practicability of replacing arthroscopy by MRI in diagnosis of cartilage lesions. PATIENTS AND METHODS: 195 patients with acute or chronic knee pain were examined by reason of a pathological clinic result by MRI preoperatively. In group A (n = 86), a standard program was performed in the radiological department of German Army Hospital (sagittal STIR TSE und PD TSE, coronary und transversal T2 FFE [TR = 660 ms, TE = 18 ms, FA = 30 degrees, 512er-Matrix]), in 21 patients (subgroup AK) a cartilage specific sequence (fs T1 W FFE) without gadolinium was added. Patients in group B (n = 88) were examined in a private outpatient clinic (sagittal T1 SE, T2 SE and T2 FLASH [TR = 608 ms, TE = 18 ms, FA = 20 degrees, 256er-Matrix]) with the use of gadolinium. A clear clinical diagnosis had to be performed before MRI examination. RESULTS: 156 lesions of the cartilage were detected arthroscopically. The sensitivity of the examination was in group A 33 %; group B 53 %; group AK 38 %, specificity in group A 99 %; group B 98 % and group AK 98 %. The positive and negative predictive values were in group A 75 %/98 %; group B 48 %/98 % and in group AK 50 %/97 %. CONCLUSION: MRI was not able to detect reliable cartilage lesions. Until now, arthroscopy is the golden standard to detect cartilage lesions.     

Is knee osteotomy still indicated in knee osteoarthritis?

This study was undertaken to investigate whether high tibial osteotomy (HTO) still had a role in the treatment of osteoarthritis of the knee joint. The author has performed photoelasticity studies which confirmed abnormal stress distribution over the joint, as soon as its mechanical axis was deviated and the joint line had an obliquity over 10 degrees. High tibial osteotomy to correct varus or valgus deformity restores a symmetrical stress distribution and represents the only etiological treatment of secondary osteoarthritis of the knee. Two hundred and fifty HTO's were performed between 1971 and 1985 for osteoarthritis of the knee. The short-term result was good or very good in 75%, fair in 20% and poor in 5%. Fair and poor results were related to insufficient correction, to infection or mostly to incorrect indications. In 152 cases with a good or very good short term result, a further evaluation was made between 8 years and 15 years after operation. It was noted that osteoarthritis had been arrested in 105 cases (69%) whereas it had deteriorated in 47 cases. The main factors associated with further deterioration were insufficient correction and persistence of joint line obliquity. Provided on optimal correction is achieved (3 degrees to 6 degrees hypercorrection in valgus osteotomy, 0 degree in varus osteotomy) and provided a horizontal joint line is restored, HTO performed in good indications (Ahlback grade I or II) may provide good results for at least 10 to 15 years.     

Arthroscopic synovectomy of the knee: Is it helpful?

We performed 211 arthroscopic synovectomies over a 10-year period. The results were assessed at follow-up of at least 2 years using the criteria of pain, synovitis, and effusion, range of motion and function. In rheumatoid knees (112 cases), we had good or excellent results in 80%. However, in seronegative arthritides (32 cases), only 60% were successful. Pigmented villonodular synovitis was successfully treated with an 11% recurrence rate (19 cases total). Synovial chondromatosis (17 cases) had no recurrences. In patients with nonspecific synovitis or posttraumatic synovitis, the synovitis was improved in 60% but only half the patients had pain relief and good function. Looking specifically at the posterior portals, there were five complications, all related to the posteromedial portal involving the saphenous nerve and vein. Overall excellent results can be achieved with due care and attention to detail.     

Is Port Site Resection Necessary in the Surgical Management of Gallbladder Cancer?

Background  

In selected patients with incidental gallbladder carcinoma (GBCA) diagnosed after laparoscopic cholecystectomy (LC), definitive resection is warranted. Port site excision has been advocated but remains controversial.     

Transforming growth factor-β in calcium alginate beads for the treatment of articular cartilage defects in the rabbit

Purpose: Articular cartilage has only limited capability for intrinsic repair. The use of growth factors has been suggested to improve the repair of cartilage after injury. Reliable delivery systems for these agents are needed. In this study we tested calcium alginate for the delivery of TGF-β in the treatment of osteochondral defects in the rabbit knee. Type of Study: Randomized trial animal study and basic science study. Methods: In vitro, to establish the kinetics of TGF-β release from the alginate, ¹²⁵I- labeled TGF-β was suspended in 1.2% sodium alginate at concentrations of 1 μg/mL and 10 μg/mL. Beads were formed from 50 μL aliquots and placed into standard culture medium by immersion in calcium chloride solution and incubated at 37° C. A gamma counter was used to measure the amount of TGF-β that was released into the medium at various time points. In vivo, osteochondral defects were created in the trochlear grooves of 32 New Zealand White rabbits. Defects were treated with plain alginate or with alginate containing TGF-β at 20 ng/mL or 2,000 ng/mL. Untreated defects served as a control. Animals were killed after 6 and 12 weeks. Knee joints were evaluated grossly with a 12-point grading scale. Histologic sections of the repair tissue were stained with Safranin O and evaluated using a 24-point grading scale by 2 independent blinded observers. Mean scores and standard deviations were calculated. P values were determined using the Student t test. Results: The TGF-β was released at a surprisingly slow but steady rate. Release rates extrapolated from the gamma counter measurements were 0.25% per hour and 0.33% per hour, for the 1 μg/mL and 10 μg/mL beads, respectively. Gross analysis scores at 6 and 12 weeks resulted in higher scores for both TGF-β groups without reaching statistical significance. The lower TGF-β concentration reached the highest scores, whereas the higher concentration (2,000 ng/mL) resulted in increased osteophyte formation. Histologic analysis at 6 weeks resulted in average scores ranging from 14.5 for empty defects and 18.1 for alginate-treated defects, to 20.0 and 20.3 for the 2,000 ng/mL and 20 ng/mL TGF-β groups, respectively (P <.05). At 12 weeks, histologic scores ranged from 14.9 for empty and 14.5 for alginate to 20.1 and 20.5 for the 2,000 ng/mL and 20 ng/mL TGF-β groups, respectively (P <.05). These results indicate a significant improvement of the quality of the repair tissue at 6 and 12 weeks with TFG-β treatment, especially at the lower concentration. Conclusions: The use of alginate allows the controlled delivery of TGF-β selectively to the site of injury, potentially avoiding systemic side effects. Furthermore, treatment with TGF-β appears to improve the repair of articular cartilage defects. Longer-term studies are needed to assess whether the benefits of the TGF-β treatment can be sustained.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 18, No 8 (October), 2002: pp 892–900     

Giant cell tumor of bone: Is curettage the answer?

Background:

Giant cell tumors (GCT) are neoplasms of mesenchymal stromal cells with varied manifestations. There is no uniform accepted treatment protocol for these tumors,

Materials and Methods:

49 cases of proven giant cell tumors of appendicular skeleton, 27 prospective and 22 retrospective constituteed this study. The retrospective cases were collected by using computerized data base collection method. The patients were evaluated clinically, radiologically and by histology. Companacci grading and Enneking staging was used in the study. Two treatment modalities were used a) extended curettage (with/ without bone grafting/ cementation) or b) wide excision and reconstruction with a prosthesis or arthrodesis. Functional evaluation was done by Enneking''s system. Chi square tests, mann-whitney test and ANOVA were used for statistical analysis.

Results:

The average age was 26.82 years (16-50 years). 25 patients (51%) were recurrent GCT at presentation. The commonest site was lower end of femur (16 cases, 32.65%) and upper end of tibia (13 cases, 26.53%). 40 (81.63%) tumors had less than 5 mm of subchondral bone free of tumor. 35 (71.43%) tumors were Enneking''s surgical stage III and companacci grade III. Pathological fractures were seen in 12 (24.49%) cases. Intra-lesional currettage was used in 28 and enbloc excision in 19 patients and 2 (4.08%) underwent amputation. The average follow up period was 18.6 months (range 2-84). One recurrence was seen in a grade III recurrent distal radial lesion in the intralesional curettage group (3.57%) Enneking''s functional score with intralesional curettage (25.41) was better than enbloc excision (21.37). Enbloc excision had higher rates of infections (36.84 % Vs 25%) and soft tissue coverage problems (21.05% Vs 0).

Conclusion:

Intralesional therapy has a better functional outcome and less complications than enbloc excision, albeit with a high recurrence rate which can however be effectively treated with repeat extended curettage.