The effects of beveling the margins of articular cartilage defects in immature dogs

Microscale strain mapping demonstrates the importance of interface slope in the mechanics of cartilage repair

Achieving lateral integration of articular cartilage repair tissue with surrounding native cartilage remains a clinical challenge. Histological and bulk mechanical studies have identified extracellular matrix components that correlate with superior failure strength, but it is unclear how local changes in geometry and composition at the repair interface affect tissue strains under physiologic loading. Here, we investigated the effects of local compositional and interface geometry on lateral cartilage repair integration by coupling microscale Raman spectroscopy and confocal elastography to measure tissue strains under compressive and shear loading. Histological integration assessments did not have significant relationships with interface strains under compressive loading (p > 0.083) and only the perimeter attachment score was trending towards statistical significance with the |E_xy| strain tensor under shear loading (p = 0.050). Interface slope had a stronger correlation with local tissue strains under compressive and shear loading compared to compositional measures of GAG, collagen, or proteins (compressive loading |E_yy| tensor: R² = 0.400 (interface slope), 0.005 (GAG), 0.024 (collagen), and 0.012 (protein); shear loading |E_xy| tensor: R² = 0.457 (interface slope), 0.003 (GAG), 0.006 (collagen), and 0.000 (total protein)). These data support surgical publications detailing the need for vertical walls when debriding chondral defects. Current histological integration assessments and local compositional measures were insufficient for identifying the variation in interface strains under compressive and shear loading. Thus, our data points to the importance of controlling interface geometry at the time of surgery, which has implications for cartilage repair integration and long-term healing.

Is There a Role for Cartilage Imaging in Athletes?

This article reviews implications for cartilage imaging in athletes in the setting of (1) acute chondral injury diagnosis, (2) evaluation and follow-up of conservative and surgical therapy, and (3) evaluation of cartilage as a surrogate for meniscal function and joint stability. Focal knee cartilage defects are common in athletic populations. Athletes with articular cartilage injury may initially be able to return to sport with conservative therapy; however, a reduction of athletic ability and progression to osteoarthritis is expected in athletes with untreated severe chondral injury. For diagnostic and pre- and postsurgical evaluation purposes, morphological magnetic resonance (MR) assessment of the articular cartilage with high-resolution protocols is crucial. Although not widely implemented for clinical use, compositional MR techniques have great potential for monitoring the development and progression of biochemical and microstructural changes in cartilage extracellular matrix before gross morphological changes occur.

Effect of Vertical or Beveled Chondral Defect Creation on Rim Deformation and Contact

OBJECTIVE

To determine biomechanical effects of knee cartilage defect perimeter morphology based on cartilage strain and opposing subchondral bone contact.

DESIGN

Articular cartilage defects were created in 5 bovine femoral condyles: group 1, 45° inner bevel with 8-mm rim; group 2, vertical with 8-mm rim; and group 3, 45° outer bevel with 8-mm base. Samples were placed into a custom-machined micro-computed tomography tube and subjected to 800 N of axial loading. DICOM data were used to calculate cartilage thickness 4 and 6 mm from the center, distance between tibial cartilage surface and femoral subchondral bone, and contact width between tibial cartilage and subchondral bone. Strain 4 mm from the center and both absolute and change in distance (mm) to subchondral bone were compared between groups 1 and 2 using paired t tests. Strain at 6 mm and distance changed, loaded distance, and contact width (mm) were compared between groups using the Friedman test with post hoc analysis using Wilcoxon signed rank test.

RESULTS

No significant differences in rim strain were noted between groups 1 and 2 at 4 mm ( P = 0.10) and between groups 1, 2, and 3 at 6 mm ( P = 0.247) from the defect center. The loaded distance was significantly different between groups 1 and 3 ( P = 0.013). No significant change in distance to the subchondral bone was found between groups ( P = 0.156). The difference in subchondral bone contact area approached but did not reach significance ( P = 0.074).

CONCLUSION

When debriding focal articular cartilage defects, establishment of an inner bevel decreases tissue deformation and contact with opposing subchondral bone.

Nonarthroplasty Options for the Athlete or Active Individual with Shoulder Osteoarthritis

The management of glenohumeral osteoarthritis is difficult in young, active individuals. After nonoperative management fails, arthroscopic debridement with concomitant procedures (eg, loose body removal, capsular release, labral debridement, synovectomy, osteophyte resection, bursectomy, subacromial decompression, microfracture, and biceps tenotomy or tenodesis) to address potential pain generators may be an option in small, contained, unipolar lesions.

Arthroscopic Cartilage Lesion Preparation in the Human Cadaveric Knee Using a Curette Technique Demonstrates Clinically Relevant Histologic Variation

PURPOSE

To examine the quality of arthroscopic cartilage debridement using a curette technique by comparing regional and morphologic variations within cartilage lesions prepared in human cadaveric knee specimens for the purpose of cartilage repair procedures. A secondary aim was to compare the histologic properties of cartilage lesions prepared by surgeons of varying experience.

METHODS

Standardized cartilage lesions (8 mm × 15 mm), located to the medial/lateral condyle and medial/lateral trochlea were created within 12 human cadaver knees by 40 orthopaedic surgeons. Participants were instructed to create full-thickness cartilage defects within the marked area, shouldered by uninjured vertical walls of cartilage, and to remove the calcified cartilage layer, without violating the subchondral plate. Histologic specimens were prepared to examine the verticality of surrounding cartilage walls at the front and rear aspects of the lesions, and to characterize the properties of the surrounding cartilage, the cartilage wall profile, the debrided lesion depth, bone sinusoid access, and the bone surface profile. Comparative analysis of cartilage wall verticality measured as deviation from perpendicular was performed, and Spearman's rank correlation analysis was used to examine associations between debrided wall verticality and surgeon experience.

RESULTS

Mean cartilage wall verticality relative to the base of the lesion was superior at the rear aspect of the lesion compared to the front aspect (12.9° vs 29.2°, P < .001). Variability was identified in the morphology of the surrounding cartilage (P < .001), cartilage wall profile (P = .016), debrided lesion depth (P = .028), bone surface profile (P = .040), and bone sinusoid access (P = .009), with sinusoid access identified in 42% of cases. There was no significant association of cartilage lesion wall verticality and surgeon years in practice (r_s = 0.161, P = .065) or arthroscopic caseload (r_s = -0.071, P = .419).

CONCLUSIONS

Arthroscopic cartilage lesion preparation using standard curette technique in a human cadaveric knee model results in inferior perpendicularity of the surrounding cartilage walls at the front aspect of the defect, compared to the rear aspect. This technique has shown significant variability in the depth of debridement, with debridement depths identified as either too superficial or too deep to the calcified cartilage layer in more than 60% of cases in this study. Surgeon experience does not appear to impact the morphologic properties of cartilage lesions prepared arthroscopically using ring curettes. CLINICAL RELEVANCE: To optimize restoration of hyaline-like cartilage tissue, careful attention to prepared cartilage lesion morphology is advised when arthroscopically performing cartilage repair, given the tendency for standard curette technique to create inferior verticality of cartilage walls at the front of the lesion, and the variable depth of debridement achieved.

Morphologic Properties of Cartilage Lesions in the Knee Arthroscopically Prepared by the Standard Curette Technique Are Inferior to Lesions Prepared by Specialized Chondrectomy Instruments

BACKGROUND

Cartilage lesion preparation is an important component to cartilage repair procedures, given the effect of prepared lesion morphology on the formation of durable and well-integrated repair tissue.

PURPOSE

To compare the quality of arthroscopic cartilage lesion debridement performed by (1) the standard curette (SC) technique and (2) specialized chondrectomy (CM) instruments, to provide technical guidance for optimization of cartilage lesion preparation in the setting of arthroscopic cartilage repair.

STUDY DESIGN

Controlled laboratory study.

METHODS

Articular cartilage lesions of standardized size (8 × 15 mm) were demarcated within the trochlea and femoral condyles of 20 human cadaver knee specimens. Orthopaedic surgeons performed arthroscopic lesion preparation using 2 techniques that consisted of SC preparation and preparation by CM instruments. A histologic comparative analysis was performed within each treatment group and between treatment groups to evaluate the morphology of prepared cartilage defects.

RESULTS

The mean angle deviation from perpendicular of the cartilage wall at the front of the prepared cartilage lesions was significantly greater in the SC group versus the CM group (29.8° ± 21.4° vs 7.7° ± 7.6°, P < .001). In lesions prepared via the SC technique, the cartilage walls at the front of the prepared lesions were significantly less perpendicular than the cartilage walls at the rear of the lesions (29.8° ± 21.4° vs 11.0° ± 10.3°, P < .001), whereas lesions prepared by the CM technique demonstrated comparable verticality of surrounding cartilage walls at the front and rear aspects of the lesions (7.7° ± 7.6° vs 9.4° ± 12.3°, P = .827). Depth of lesion debridement was accomplished to the target level by the CM technique in 86% of prepared lesions, compared with 34% of lesions in the SC group. The prepared cartilage wall profile was characterized as the most ideal morphology in 55% of prepared lesions in the CM group, as opposed to 10% in the SC group.

CONCLUSION

Arthroscopic cartilage lesion preparation with SC instruments results in superior perpendicularity of surrounding cartilage walls to subchondral bone and greater consistency of debrided lesion depth, as compared with the standard debridement technique with curettes.

CLINICAL RELEVANCE

Arthroscopic preparation using standard curette technique leads to suboptimal morphologic characteristics of prepared lesions that likely affect the quality of repair tissue, compared to preparation using specialized chondrectomy instruments.

Osteochondrosis dissecans of the tarsus in Labrador Retrievers: Clinical signs, radiological data and force plate gait evaluation after surgical treatment

Objectives: To report the outcome of unilateral surgery, by a plantaromedial approach, in 15 Labrador Retrievers with osteochondrosis dissecans (OCD) of the medial trochlear ridge of the talus. To evaluate the influence on outcome of age at surgery, bilateral involvement, periarticular soft tissue increase (PSI), osteophyte size (OS), decrease of range of joint motion and follow-up. To assess the extent of tarsal hyperextension in the standing dog.

Methods: A retrospective clinical and radiographic study was conducted and the posttreatment gait was analysed using a force plate. Ground reaction force (GRF) data were compared with data derived from 24 healthy Labrador Retrievers (control group).

Results: Six dogs had an excellent or good clinical result. Significant differences were found between the patients and the control group for many GRF data. Propulsive and vertical forces significantly decreased in the operated limb and increased in the contralateral pelvic and ipsilateral or both thoracic limbs. The lameness was significantly correlated to the OS postoperatively, the range-of-motion, the PSI, the length of the follow-up period, and the vertical ground force. No hyperextension in stance was recorded.

Clinical significance: Although most dogs improved, the prognosis remains guarded. This seems to be independent of age, bilateral involvement, or preoperative OS in these dogs. No relation between medial talar OCD and tarsal hyperextension in stance was found in these dogs.

Cartilage defect repair in horses: Current strategies and recent developments in regenerative medicine of the equine joint with emphasis on the surgical approach

Chondral and osteochondral lesions due to injury or other pathology are highly prevalent conditions in horses (and humans) and commonly result in the development of osteoarthritis and progression of joint deterioration. Regenerative medicine of articular cartilage is an emerging clinical treatment option for patients with articular cartilage injury or disease. Functional articular cartilage restoration, however, remains a major challenge, but the field is progressing rapidly and there is an increasing body of supportive clinical and scientific evidence. This review gives an overview of the established and emerging surgical techniques employed for cartilage repair in horses. Through a growing insight in surgical cartilage repair possibilities, surgeons might be more stimulated to explore novel techniques in a clinical setting.

Development of a Valid and Reliable Knee Articular Cartilage Condition-Specific Study Methodological Quality Score

BACKGROUND

Condition-specific questionnaires are important components in evaluation of outcomes of surgical interventions. No condition-specific study methodological quality questionnaire exists for evaluation of outcomes of articular cartilage surgery in the knee.

PURPOSE

To develop a reliable and valid knee articular cartilage-specific study methodological quality questionnaire.

STUDY DESIGN

Cross-sectional study.

METHODS

A stepwise, a priori-designed framework was created for development of a novel questionnaire. Relevant items to the topic were identified and extracted from a recent systematic review of 194 investigations of knee articular cartilage surgery. In addition, relevant items from existing generic study methodological quality questionnaires were identified. Items for a preliminary questionnaire were generated. Redundant and irrelevant items were eliminated, and acceptable items modified. The instrument was pretested and items weighed. The instrument, the MARK score (Methodological quality of ARticular cartilage studies of the Knee), was tested for validity (criterion validity) and reliability (inter- and intraobserver).

RESULTS

A 19-item, 3-domain MARK score was developed. The 100-point scale score demonstrated face validity (focus group of 8 orthopaedic surgeons) and criterion validity (strong correlation to Cochrane Quality Assessment score and Modified Coleman Methodology Score). Interobserver reliability for the overall score was good (intraclass correlation coefficient [ICC], 0.842), and for all individual items of the MARK score, acceptable to perfect (ICC, 0.70-1.000). Intraobserver reliability ICC assessed over a 3-week interval was strong for 2 reviewers (≥0.90).

CONCLUSION

The MARK score is a valid and reliable knee articular cartilage condition-specific study methodological quality instrument.

CLINICAL RELEVANCE

This condition-specific questionnaire may be used to evaluate the quality of studies reporting outcomes of articular cartilage surgery in the knee.

Surgical treatment options for the young and active middle-aged patient with glenohumeral arthritis

The diagnosis and treatment of symptomatic chondral lesions in young and active middle-aged patients continues to be a challenging issue. Surgeons must differentiate between incidental chondral lesions from symptomatic pathology that is responsible for the patient's pain. A thorough history, physical examination, and imaging work up is necessary and often results in a diagnosis of exclusion that is verified on arthroscopy. Treatment of symptomatic glenohumeral chondral lesions depends on several factors including the patient's age, occupation, comorbidities, activity level, degree of injury and concomitant shoulder pathology. Furthermore, the size, depth, and location of symptomatic cartilaginous injury should be carefully considered. Patients with lower functional demands may experience success with nonoperative measures such as injection or anti-inflammatory pharmacotherapy. When conservative management fails, surgical options are broadly classified into palliative, reparative, restorative, and reconstructive techniques. Patients with lower functional demands and smaller lesions are best suited for simpler, lower morbidity palliative procedures such as debridement (chondroplasty) and cartilage reparative techniques (microfracture). Those with higher functional demands and large glenohumeral defects will usually benefit more from restorative techniques including autograft or allograft osteochondral transfers and autologous chondrocyte implantation (ACI). Reconstructive surgical options are best suited for patients with bipolar lesions.

The effects of focal articular defects on cartilage contact mechanics

Focal damage to articular cartilage is common in arthroscopy patients, and may contribute to progressive tissue degeneration by altering the local mechanical environment. The effects of a focal defect, which may be oriented at various orientations relative to the subchondral bone, on the dynamics of cartilage contact and deformation are unclear. The objective of this study was to elucidate the effect of experimental full thickness focal defects, oriented at 80 degrees or 100 degrees relative to the subchondral bone, on intratissue strain and surface sliding of opposing cartilage surfaces during compression and stress relaxation. Pairs of intact bovine osteochondral blocks were compressed uniaxially by 20%, and allowed to stress relax. Tissue deformation was recorded by video microscopy. A full-thickness defect (with either 80 degrees or 100 degrees edges) was created in one block from each pair. Blocks were allowed to reswell and retested. Defect edges were then recut with the opposite orientation, allowed to reswell, and retested again. Stained nuclei were tracked by digital image correlation and used to quantify cartilage strains and surface sliding. The results indicated that loading of intact samples caused axial strain magnitudes that decreased with depth and relatively little sliding. With loading of samples containing defects, strain magnitudes were elevated in cartilage adjacent to, and opposing, defects. For samples with edge orientations of 100 degrees, sliding magnitudes were increased over surfaces adjacent to defects. These local mechanical changes due to full-thickness articular cartilage defects may contribute to altered chondrocyte metabolism, tissue damage, or accelerated wear.

Nonarthroplasty alternatives for the treatment of glenohumeral arthritis

Although most glenohumeral cartilaginous lesions are incidental findings and well tolerated, a symptomatic cartilage injury in a young, active individual remains a challenge. The diagnosis of this symptomatic lesion is difficult, and is usually only arrived at once other shoulder comorbidities and sources of glenohumeral pain are ruled out. Once diagnosed, a variety of treatment options are available which include palliative, reparative, restorative, and reconstruction techniques. The smallest lesions are amenable to reparative strategies such as marrow-stimulation, stimulating a fibrocartilaginous response. Larger lesions and those that have failed reparative techniques may be candidates for restorative or reconstruction procedures to replace damaged cartilage with hyaline-like tissue. The presence of bipolar injury may require the use of biologic interpositional arthroplasty. This review describes the challenges associated with the diagnosis and management of glenohumeral arthritis, and provides a treatment framework for use in these challenging patients.

Traumatic Luxations of the Appendicular Skeleton

Traumatic luxation of joints of the appendicular skeleton is common.Timely and accurate identification of the luxation is essential to restoring normal function. Physical examination and radiographic assessment are commonly utilized for accurate identification and categorization. Conservative and surgical techniques are employed for treatment of luxations solely and in combination. Selection of appropriate reparative techniques is dependent on the joint injured as well as on other joint- and injury-specific factors.

Nonarthroplasty treatment of glenohumeral cartilage lesions

Treatment of young, active persons with symptomatic cartilage lesions of the glenohumeral joint represents a significant challenge. Diagnosis of glenohumeral chondral defects is not always straightforward and effective treatment requires familiarity with a number of techniques. Low-demand individuals may accept palliative therapy in the form of arthroscopic debridement as a temporizing solution. However, younger, high-demand individuals require a careful, stepwise approach that includes reparative, restorative, and reconstructive strategies. Reparative strategies use marrow-stimulation techniques to induce formation of fibrocartilage. Restorative tactics attempt to replace damaged cartilage with hyaline or hyaline-like tissue using osteochondral or chondrocyte transplantation. Large lesions that are not candidates for reparative or restorative procedures can be approached using reconstruction methods such as biologic resurfacing. This review examines causes of chondral injury in the glenohumeral joint, discusses diagnostic strategies, and presents a practical framework including palliative, reparative, restorative, and reconstructive options with which one can formulate a treatment plan for these patients.

Cartilage restoration, part 1: basic science, historical perspective, patient evaluation, and treatment options

Surgical procedures designed to treat focal chondral lesions are evolving and are supported by basic science principles of cartilage physiology and known responses to injury. Selecting the proper treatment algorithm for a particular patient depends on careful patient evaluation, including the recognition of comorbidities such as ligamentous instability, deficient menisci, or malalignment of the mechanical limb axis or extensor mechanism. These comorbidities may need to be treated in conjunction with symptomatic chondral injuries to provide a mutually beneficial effect. A central tenet of cartilage restoration is to leave future treatment options available should they become necessary. In this article (part 1), the authors review the basic science of chondral injuries, the historical perspective of the available surgical options, and present guidelines for patient evaluation and treatment.

Osteochondritis dissecans of the humeral head

Osteochondritis dissecans (OSD) of the humeral head is frequently identified as a cause of forelimb lameness in the dog. Surgical removal of the cartilaginous flap remains the preferred method of treatment in dogs demonstrating clinical signs of lameness and pain. This article reviews the pertinent literature regarding humeral head OSD, present diagnostic and therapeutic options, and surgical treatment of this condition.

The effect of exercise on the healing of articular cartilage defects in the equine carpus

Arthroscopic surgery was performed on 12 horses (2-4 years of age) to create a 7 x 14 mm full-thickness cartilage defect in one radial carpal bone and in the contralateral third carpal bone. Six horses remained confined to a small paddock and six horses underwent a program of increasing exercise consisting of walking, trotting, and cantering for 13 weeks. All lesions showed evidence of healing at week 6 that progressed to more complete healing at week 13. There was no difference in the amount of repair tissue covering the defect. Histologically, the lesions healed with a combination of fibrous tissue and fibrocartilage. The repair tissue was significantly thicker in the exercised horses but there was no difference in repair quality. It was concluded that radial carpal and third carpal lesions have an equal ability to heal and that early postoperative exercise is not detrimental to the repair tissue within these carpal cartilage defects.