Is technique performance a prognostic factor in bone marrow stimulation of the talus?

Outcomes of Bone Marrow Stimulation for Secondary Osteochondral Lesions of the Talus Equal Outcomes for Primary Lesions

OBJECTIVE

To compare clinical, sports, work, and radiological outcomes between primary and secondary osteochondral lesions of the talus (OLTs; <15 mm) treated with arthroscopic bone marrow stimulation (BMS).

DESIGN

Secondary OLTs were matched to primary OLTs in a 1:2 ratio to assess the primary outcome measure-the Numeric Rating Scale (NRS) during activities. Secondary outcomes included the pre- and 1-year postoperative NRS at rest, American Orthopaedic Foot and Ankle Society score, Foot and Ankle Outcome Score subscales, and the EQ-5D general health questionnaire. The rates and time to return to work and sports were collected. Radiological examinations were performed preoperatively and at final follow-up using computed tomography (CT).

RESULTS

After matching, 22 and 12 patients with small (<15 mm) OLTs were included in the primary and secondary groups, respectively. The NRS during activities was not different between primary cases (median: 2, interquartile range [IQR]: 1-4.5) and secondary cases (median: 3, IQR: 1-4), P = 0.5. Both groups showed a significant difference between all pre- and postoperative clinical outcome scores, but no significant difference between BMS groups postoperatively. The return to sport rate was 90% for primary cases and 83% for secondary cases (P = 0.6). All patients returned to work. Lesion filling on CT was complete (67% to 100%) in 59% of primary cases and 67% of secondary cases (P = 0.6).

CONCLUSION

No differences in outcomes were observed between arthroscopic bone marrow stimulation in primary and secondary OLTs at 1-year follow-up. Repeat BMS may therefore be a viable treatment option for failed OLTs in the short term.

Feasibility Study to Determine if Microfracture Surgery Using Water Jet Drilling Is Potentially Safe for Talar Chondral Defects in a Caprine Model

OBJECTIVE

Surgical microfracture is considered a first-line treatment for talar osteochondral defects. However, current rigid awls and drills limit access to all locations in human joints and increase risk of heat necrosis of bone. Using a flexible water jet instrument to drill holes can improve the reachability of the defect without inducing thermal damage. The aim of this feasibility study is to determine whether water jet drilling is potentially safe compared with conventional microfracture awls by studying side effects and perioperative complications, as well as the quality of cartilage repair tissue.

DESIGN

Talar chondral defects with 6-mm diameter were created bilaterally in 6 goats (12 samples). One defect in each goat was treated with microfracture created with conventional awls, the contralateral defect was treated with holes created with 5-second water jet bursts at a pressure of 50 MPa. Postoperative complications were recorded and after 24 weeks analyses were performed using the ICRS (International Cartilage Repair Society) macroscopic score and modified O'Driscoll histological score.

RESULTS

Several practical issues using the water jet in the operating theatre were noted. Water jet drilling resulted in fibrocartilage repair tissue similar to the repair tissue from conventional awls.

CONCLUSIONS

These results suggest that water jet drilling gives adequate fibrocartilage repair tissue. Furthermore, the results highlight essential prerequisites for safe application of surgical water jet drilling: stable water pressure, water jet beam coherence, stable positioning of the nozzle head when jetting, and minimizing excessive fluid extravasation.

Augmented Microfracture Technique Versus Microfracture in Talar Cartilage Restoration: A Systematic Review and Meta-Analysis

The aim of this meta-analysis was to compare the efficacy and safety between the microfracture (MFx) and augmented microfracture (MFx+) techniques for articular cartilage defects of the talus (OLTs). PubMed and EMBASE were searched from January 1950 to October 2020. Only randomized controlled trials, quasi-randomized controlled trials, and observational studies (retrospective and prospective) applying MFx and MFx+ techniques to treat talar cartilage defects were selected. Ten trials with 492 patients were included. There was significant difference in final American Orthopaedic Foot & Ankle Society score (AOFAS) (mean difference [MD] = 7.07; 95% confidence interval [CI], 3.70-10.44; p < .01), AOFAS change (MD = 7.97; 95% CI, 4.27-11.66; p < .01), visual analog scale (VAS) change score (MD = 0.44; 95% CI, 0.29-0.59; p < .01), Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score (MD = 12.51; 95% CI, 7.16-17.86; p < .01), complication (RR = 0.33; 95% CI, 0.16-0.69; p < .01), and revision (Relative risk = 0.34; 95% CI, 0.15-0.77; p < .05), between the MFx and MFx+ groups. No significant difference was observed for final VAS pain score (MD = -0.53; 95% CI, -1.2 to 1.05; p = .13) and Tegner scale (MD = 0.31; 95% CI, -1.05 to 1.66; p = .66) in either group. Our results suggest that augmented microfracture is superior to microfracture alone in the treatment of talar OLTs based on the AOFAS, MOCART, VAS score, complication rate, and revision ratio. Therefore, microfracture with augmentation should be considered as a treatment for OLTs of talus. However, more randomized trials are still required to determine the long-term superiority of MFx+.

Arthroscopic Treatment of Osteochondral Lesions of the Talus in a Pediatric Population: A Minimum 2-Year Follow-up

BACKGROUND

Treatment of osteochondral lesions of the talus (OLTs) in children presents a difficult clinical challenge, with few large series reported.

PURPOSE

To evaluate functional and radiographic outcomes for children and adolescents undergoing arthroscopic treatment of symptomatic OLT with a minimum follow-up of 2 years.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients were identified who had symptomatic OLT treated arthroscopically with marrow stimulation techniques. Inclusion criteria were age ≤18 years, symptomatic chronic OLT as the surgical indication, failure of nonoperative treatment, and minimum follow-up of 24 months. Outcome measures included Foot Function Index, American Orthopaedic Foot and Ankle Society Hindfoot Score, Tegner Activity Scale, 36-Item Short Form Health Survey (Short Form-36, v 2), visual analog scale, ankle range of motion, and patient satisfaction survey. Weightbearing radiographs were compared with preoperative radiographs via an ankle arthritis classification system. Magnetic resonance imaging (MRI) was used to evaluate postoperative lesion characteristics per the MOCART scale (magnetic resonance observation of cartilage repair tissue). The size, location, lesion stability, traumatic etiology, skeletal maturity, and length of follow-up were recorded and analyzed through univariate logistic regression.

RESULTS

The study group consisted of 22 patients (11 male, 11 female) with a mean age of 14.4 years (range, 8-18 years) and a mean follow-up of 8.3 years (range, 2-27 years). Of 22 patients, 20 were satisfied with the results from surgery and would recommend it to others. Mean follow-up visual analog scale for pain was reported as 2.2 on a 10-point scale, and mean American Orthopaedic Foot and Ankle Society score at follow-up was 86.6. Mean postoperative Foot Function Index scores for the study group were as follows: pain, 17.1; disability, 16.5; activity, 4.7; and overall, 38.7. Mean Short Form-36 physical component score was 50.7. Postoperative radiographs indicated a van Dijk osteoarthritis grade of 0 in 56%, I in 38%, II in 6%, and III in 0%. Postoperative MRI MOCART scores showed complete filling of the cartilage in 27% of cases, complete graft integration in 22%, and intact repair surface in 22%, with a mean MOCART score of 48.0. No correlation was found between radiographic and MRI findings and clinical outcomes. None of the prognostic factors were significantly associated with patient satisfaction, progression of arthritis, or MOCART scores.

CONCLUSION

Arthroscopic treatment of symptomatic OLT in adolescent patients (≤18 years) demonstrated high functional outcomes, high clinical satisfaction rates, and minimal radiographic osteoarthritic progression despite low MOCART scores.

Colliding jets provide depth control for water jetting in bone tissue

In orthopaedic surgery, water jet drilling provides several advantages over classic drilling with rigid drilling bits, such as the always sharp cut, absence of thermal damage and increased manoeuvrability. Previous research showed that the heterogeneity of bone tissue can cause variation in drilling depth whilst water jet drilling. To improve control over the drilling depth, a new method is tested consisting of two water jets that collide directly below the bone surface. The expected working principle is that after collision the jets will disintegrate, with the result of eliminating the destructive power of the coherent jets and leaving the bone tissue underneath the focal point intact. To assess the working principle of colliding water jets (CWJ), the influence of inhomogeneity of the bone tissue on the variation of the drilling depth and the impact of jet time (t_wj) on the drilling depth were compared to a single water jet (SWJ) with a similar power. 98 holes were drilled in 14 submerged porcine tali with two conditions CWJ (impact angle of 30° and 90°) and SWJ. The water pressure was 70MPa for all conditions. The water jet diameter was 0.3 mm for CWJ and 0.4 mm for SWJ. t_wj was set at 1, 3, 5 and 8s. Drilling depth and hole diameter were measured using microCT scans. A non-parametric Levene's test was performed to assess a significant difference in variance between conditions SWJ and CWJ. A regression analysis was used to determine differences in influence of t_wj on the drilling depth. Hole diameter differences were assessed using a one way Anova. A significance level of p<0.05 was set. Condition CWJ significantly decreases the drilling depth variance caused by the heterogeneity of the bone when compared to SWJ. The mean depth for CWJ was 0.9 mm (SD 0.3 mm) versus 4.8 mm (SD 2.0) for SWJ. t_wj affects the drilling depth less for condition CWJ (p<0.01, R²=0.30) than for SWJ (p<0.01, R²=0.46). The impact angle (30° or 90°) of the CWJ does not influence the drilling depth nor the variation in depth. The diameters of the resulting holes in the direction of the jets is significantly larger for CWJ at 90° than for 30° or a single jet. This study shows that CWJ provides accurate depth control when water jet drilling in an inhomogeneous material such as bone. The maximum variance measured by using the 95% confidence interval is 0.6 mm opposed to 5.4 mm for SWJ. This variance is smaller than the accuracy required for bone debridement treatments (2-4 mm deep) or drilling pilot holes. This confirms that the use of CWJ is an inherently safe method that can be used to accurately drill in bones.

Comparison of clinical outcomes between arthroscopic subchondral drilling and microfracture for osteochondral lesions of the talus

PURPOSE

The objectives of this study were to compare the clinical outcomes of the two common bone marrow stimulation techniques such as subchondral drilling and microfracture for symptomatic osteochondral lesions of the talus and to evaluate prognostic factors affecting the outcomes.

METHODS

Ninety patients (90 ankles) who underwent arthroscopic bone marrow stimulation for small- to mid-sized osteochondral lesions of the talus constituted the study cohort. The 90 ankles were divided into two groups: a drilling group (40 ankles) and a microfracture group (50 ankles). Each group was matched for age and gender, and both groups had characteristics similar to those obtained from pre-operative demographic data. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and the ankle activity score (AAS) were used to compare clinical outcomes, during a mean follow-up period of 43 months.

RESULTS

The median AOFAS scores were 66.0 points (51-80) in drilling group and 66.5 points (45-81) in microfracture group pre-operatively, and these improved to 89.4 points (77-100) and 90.1 points (69-100) at the final follow-up, respectively. The median VAS scores improved at the final follow-up compared with the pre-operative condition. The median AAS for the drilling group improved from 4.5 (1-6) pre-operatively to 6.0 (1-8) at the final follow-up, while those for the microfracture group improved from 3.0 (2-8) to 6.0 (3-9). No significant differences were observed between the two groups in terms of the AOFAS scores, VAS, and AAS.

CONCLUSIONS

The arthroscopic subchondral drilling and microfracture techniques that were used to stimulate bone marrow showed similar clinical outcomes. The results of this study suggest that both techniques are effective and reliable in treating small- to mid-sized osteochondral lesions of the talus, regardless of which of the two techniques is used.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

No effect of hole geometry in microfracture for talar osteochondral defects

BACKGROUND

Débridement and bone marrow stimulation is an effective treatment option for patients with talar osteochondral defects. However, whether surgical factors affect the success of microfracture treatment of talar osteochondral defects is not well characterized.

QUESTIONS/PURPOSES

We hypothesized (1) holes that reach deeper into the bone marrow-filled trabecular bone allow for more hyaline-like repair; and (2) a larger number of holes with a smaller diameter result in more solid integration of the repair tissue, less need for new bone formation, and higher fill of the defect.

METHODS

Talar osteochondral defects that were 6 mm in diameter were drilled bilaterally in 16 goats (32 samples). In eight goats, one defect was treated by drilling six 0.45-mm diameter holes in the defect 2 mm deep; in the remaining eight goats, six 0.45-mm diameter holes were punctured to a depth of 4 mm. All contralateral defects were treated with three 1.1-mm diameter holes 3 mm deep, mimicking the clinical situation, as internal controls. After 24 weeks, histologic analyses were performed using Masson-Goldner/Safranin-O sections scored using a modified O'Driscoll histologic score (scale, 0-22) and analyzed for osteoid deposition. Before histology, repair tissue quality and defect fill were assessed by calculating the mean attenuation repair/healthy cartilage ratio on Equilibrium Partitioning of an Ionic Contrast agent (EPIC) micro-CT (μCT) scans. Differences were analyzed by paired comparison and Mann-Whitney U tests.

RESULTS

Significant differences were not present between the 2-mm and 4-mm deep hole groups for the median O'Driscoll score (p = 0.31) and the median of the μCT attenuation repair/healthy cartilage ratios (p = 0.61), nor between the 0.45-mm diameter and the 1.1-mm diameter holes in defect fill (p = 0.33), osteoid (p = 0.89), or structural integrity (p = 0.80).

CONCLUSIONS

The results indicate that the geometry of microfracture holes does not influence cartilage healing in the caprine talus.

CLINICAL RELEVANCE

Bone marrow stimulation technique does not appear to be improved by changing the depth or diameter of the holes.

Sensitivity and specificity of ultrasound in detecting (osteo)chondral defects: a cadaveric study

The long-term prognosis of cartilage lesions evolving into an eroding subchondral bone defect is not known. Longitudinal monitoring using ultrasound could assist in overall understanding. The aim of the work described in this article was to determine the feasibility of using ultrasound to detect small (osteo)chondral defects. On the anterior talar surface of 10 human cadaveric ankles, at most four defects were arthroscopically created: two pure chondral defects 3 and 1.5 mm in diameter and two osteochondral defects 3 and 1.5 mm in diameter. All ankles were examined by two observers, and their ultrasound observations were validated using computed tomography scans and photographs. Overall sensitivity was 96% for observer 1 and 92% for observer 2, and specificity for both observers was 100%. Sixty-eight percent and 79% of defect sizes were within relevant limits of agreement (-0.2 ± 1.0 mm), respectively. Ultrasound imaging has the potential to detect small (osteo)chondral defects located within visible areas.