The anterior approach for the treatment of posterior osteochondral lesions of the talus: comparison of different surgical techniques

The role of the oblique medial osteotomy angle during osteochondral fragment fixation in patients with a posteromedial osteochondral lesion of the talus

BACKGROUND

Medial malleolar osteotomy has been widely performed for posteromedial osteochondral lesions of the talus (OLT) to expose the lesion. In osteochondral fragment fixation, bioabsorbable pins should be inserted as perpendicular as possible to obtain the rigid fixation. However, the exposure of the lesion may depend on the osteotomy angle, which affects the pin insertion angles. This study aimed to analyze the relationship between pin insertion and osteotomy angles in the medial malleolar osteotomy.

METHODS

Twenty-four ankles of 23 patients were included. The malleolar bisector angle which was calculated from radiographs and actual osteotomy angles were measured on radiographs, and the pin insertion and osteotomy angles were measured using MRI. The intersection angle was defined by the tangential line of the tibial plafond and medial malleolar articular facet, and the bisector of this angle was defined as the malleolar bisector angle. The relationship between pin insertion and osteotomy angles was analyzed.

RESULTS

There was no significant difference between the actual osteotomy (55.7° ± 6.6°) and malleolar bisector angles (57.4° ± 4.3°) on the radiograph. There was a significant correlation between pin insertion and osteotomy angles (rs = 0.601). The pin insertion angle (54.3° ± 5.9°) in the lower actual osteotomy angle than the malleolar bisector angle was smaller than those in the higher actual osteotomy angle (63.4° ± 8.2°).

CONCLUSIONS

This study showed the osteotomy angle affected pin insertion angle. The osteotomy angle should not be smaller than the malleolar bisector angle at medial malleolar osteotomy to insert pins as perpendicular as possible for fixation of posteromedial OLTs.

The Frequency and Severity of Complications in Surgical Treatment of Osteochondral Lesions of the Talus: A Systematic Review and Meta-Analysis of 6,962 Lesions

OBJECTIVE

The primary aim was to determine and compare the complication rate of different surgical treatment options for osteochondral lesions of the talus (OLTs). The secondary aim was to analyze and compare the severity and types of complications.

DESIGN

A literature search was performed in MEDLINE (PubMed), EMBASE (Ovid), and the Cochrane Library. Methodological quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS). Primary outcome was the complication rate per surgical treatment option. Secondary outcomes included the severity (using the Modified Clavien-Dindo-Sink Complication Classification System for Orthopedic Surgery) and types of complications. The primary outcome, the severity, and the sub-analyses were analyzed using a random effects model. A moderator test for subgroup-analysis was used to determine differences. The types of complications were presented as rates.

RESULTS

In all, 178 articles from the literature search were included for analysis, comprising 6,962 OLTs with a pooled mean age of 35.5 years and follow-up of 46.3 months. Methodological quality was fair. The overall complication rate was 5% (4%-6%; treatment group effect, P = 0.0015). Analysis resulted in rates from 3% (2%-4%) for matrix-assisted bone marrow stimulation to 15% (5%-35%) for metal implants. Nerve injury was the most observed complication.

CONCLUSIONS

In 1 out of 20 patients treated surgically for an OLT, a complication occurs. Metal implants have a significantly higher complication rate compared with other treatment modalities. No life-threatening complications were reported.

Triplane osteotomy combined with talar non-weight-bearing area autologous osteochondral transplantation for osteochondral lesions of the talus

Background

Traditional medial malleolar osteotomy combined with autologous osteochondral transplantation (AOT) is mostly used in the treatment of osteochondral lesions of the talus (OLTs), but with high osteotomy and donor site complications. We hypothesis a new triplane medial malleolar osteotomy combined with AOT from non-weight-bearing area of the talus could be a promising choice for OLTs.

Methods

We reviewed all the symptomatic OLTs patients who received AOT with triplane osteotomy of the medial malleolus between September 2015 and December 2017 in our department. According to the inclusion and exclusion criteria, 23 patients (23 ankles), including 14 males and 9 females, were included in the study. The mean age was 35.6 years. The mean size of the lesion area was 141.5 mm². According Ferkel’s classification, including 5 type I, 11 typeIIa and 7 typeIIb. The visual analog scale (VAS) for pain during walking and the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score were used for the pre- and postoperative evaluations. In addition, the incorporation of the grafts was assessed by computed tomography (CT).

Results

All patients had a minimum follow-up of 22 months, with an average of 37.1 months. The mean time from osteotomy to full weight-bearing activity was 8.1 ± 2.3 weeks (range, 5–12 weeks). The mean VAS score improved from 5.6 ± 0.7 preoperatively to 0.7 ± 1.0 postoperatively (P < 0.01). The AOFAS ankle-hindfoot score improved significantly in all domains (P < 0.01). Twenty-one patients returned to sport at their previous level, and 2 returned at a lower level compared with preinjury (mean return to play, 7.4 months). According to CT, the medial malleolus recovered in all patients, and the graft was incorporated well. One patient suffered from flexor hallucis longus tendon discomfort due to internal fixation screw irritation posteromedial to the ankle. The general complication rate was 4.3% (1/23).

Conclusions

These results indicate that AOT combined with medial malleolus triplane osteotomy maybe a viable option for OLTs. Patients could perform weight-bearing exercise and return to sport as early as possible, with a lower rate of complications at the osteotomy site and donor site. However, the large sample well-designed prospective comparative studies are still needed.

Location Distribution of 2,087 Osteochondral Lesions of the Talus

OBJECTIVE

The primary aim of this study was to evaluate the exact location distribution in patients with osteochondral lesions of the talus (OLTs) using a 9-grid scheme. The secondary aim is to match lesion location to lesion size, arthroscopic or open operation, and trauma occurrence.

METHODS

A systematic review was performed in the databases PubMed, EMBASE, and Cochrane. Search terms consisted of "talus" and "osteochondral lesion." Two independent reviewers evaluated search results and conducted the quality assessment using the Methodological Index for Non-Randomized Studies (MINORS). Primary outcome measure was OLT location in the 9 zone-grid. Secondary outcome measures were OLT size in 9-zones, preoperative radiological modality use, demographic lesion size variables as well as open or arthroscopic treatment.

RESULTS

Fifty-one articles with 2,087 OLTs were included. Heterogeneity concerning methodological nature was observed and methodological quality was low. The posteromedial (28%) and centromedial (31%) zones combined as one location was the location with the highest incidence of OLTs with a rate of 59%. Individual OLT size was reported for only 153 lesions (7%). Preoperative combination of X-ray and magnetic resonance imaging (MRI), and/or computed tomography (CT) was reported in 20 studies (43%). Trauma was reported in 78% of patients. Furthermore, 67% was treated arthroscopically and 76% received primary OLT treatment.

CONCLUSION

The majority of OLTs are located in the posteromedial and centromedial zone, while the largest OLTs were reported in the centrocentral zone. Further research is required to identify the prognostic impact of location occurrence on the outcomes following OLT treatment.

Outcomes of arthroscopic bone graft transplantation for Hepple stage V osteochondral lesions of the talus

Background

Based on MRI imaging findings, osteochondral lesions of the talus (OLT) can be classified into five stages, in which stage V represents OLT with subchondral cyst formation. The aim of this study was to evaluate the outcomes of patients undergoing arthroscopic transplantation of calcaneus bone graft for Hepple stage V OLT.

Methods

This retrospective study included 24 patients with Hepple stage V OLT (15 men and 9 women), with an average age of 39.8±12.9 years old. The mean follow-up period was 18.9±11.8 months. At this follow-up, all patients were clinically evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) score, the Karlsson Ankle Function Score (KAFS), the Tegner score, and the visual analogue scale (VAS). Furthermore, 14 patients underwent MRI imaging examinations, and the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) 2.0 score was assessed.

Results

The AOFAS score, KAFS, Tegner activity score, and VAS pain score (preoperative: 62.2, 60.4, 2.1, and 6.2, respectively; postoperative: 92.8, 88.5, 4.2, and 1.6, respectively) improved significantly (P=0.0001). The MRI-based MOCART score of the articular cartilage repair tissue after surgery was 68±14.8.

Conclusions

Arthroscopic transplantation of calcaneus bone graft for Hepple stage V OLT could obtain satisfying clinical and radiological outcomes in the short-term.

Electromagnetic navigation reduces radiation exposure for retrograde drilling in osteochondrosis dissecans of the talus

Background

Retrograde drilling in osteochondrosis dissecans (OCD) is a widely used surgical intervention. A radiation-free electromagnetic navigation system (ENS)-based method was compared with the standard freehand fluoroscopic (SFF) method regarding clinical applicability.

Methods

We performed a clinical cohort study at a department of Orthopaedics in a Level 1 children’s hospital with 40 patients (20 SFF and 20 ENS). Retrograde drilling of the talar dome was used in patients with unstable medial OCD (MRI stage 2 according to Hepple’s revised classification; stage 2 according to the International Cartilage Repair Society). The outcome measurements were: (a) Intraoperative fluoroscopy exposure and length of surgery and (b) Postoperative serial follow-up MRIs every 6 months.

Results

22 female and 18 male patients aged 13.8 ± 1.6 years (range: 11–17 years) were included. Using the ENS technique, length of surgery was significantly reduced to 20.2 ± 6.4 min compared to 36.1 ± 11.8 min (p < 0.01) for the SFF technique. The average x-ray radiation time for the SFF technique was 23.5 ± 13.5 sec and 1.9 ± 1.7 sec for the ENS technique (p < 0.01). Radiation exposure was significantly reduced from 44.6 ± 19.7 mSv (SFF technique) to 5.6 ± 2.8 mSv (ENS technique) (p < 0.01). Intraoperative perforation of cartilage occurred once in the SFF group. Correct placement of the drilling channel was verified in all patients on follow-up MRI after six months and a timely healing was seen after two years.

Conclusions

The ENS method provides for a significant reduction in length of surgery and radiation exposure. ENS was without intraoperative cartilage perforation. The clinical and radiological follow-up parameters are comparable for SFF- and ENS-guided retrograde drilling.

Trial registration

WF – 085/20, 05/2020 “retrospectively registered” https://www.aerztekammer-hamburg.org/ethik_kommission.html.

Autologous matrix-induced chondrogenesis for the treatment of osteochondral lesions of the talus: A systematic review

This study was performed to determine whether Autologous Matrix-Induced Chondrogenesis (AMIC) is an effective and safe treatment option for patients with symptomatic Osteochondral defects of the Talus (OCTs) and to identify factors that influence the clinical outcome. A systematic review of the literature was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Three reviewers independently conducted the literature search using the MEDLINE/PubMed database and the Cochrane Database of Systematic Reviews. The databases were queried using the terms “autologous” AND “matrix” AND “induced” AND “chondrogenesis.” Thirteen studies were eligible for review. All studies that compared the preoperative and postoperative mean values of different clinical/functional scores showed significant clinical improvement. The final postoperative mean Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score ranged from 50.9 to 74.5. The included studies indicated that age and body mass index may have a detrimental impact on the postoperative outcome. A higher re-intervention rate is expected with the open technique, mainly because of hardware removal after malleolar osteotomy. This data analysis demonstrated that both arthroscopic and open AMIC procedures are effective and safe for the treatment of OCTs. Level IV, systematic review of therapeutic studies

All-arthroscopic AMIC® (AT-AMIC) for the treatment of talar osteochondral defects: A short follow-up case series

INTRODUCTION

Various procedures have been used to treat osteochondral lesions of the talus. Among the new alternatives to treat these lesions, Autologous Matrix-Induced Chondrogenesis (AMIC^®) has proven to provide satisfactory results through medium-term follow-up. The aim of this study is to report early post-operative clinical results of patients submitted to the AT-AMIC^® technique and autologous bone graft, when necessary, for OLT's at a eight-month minimum follow-up.

METHODS

This is case series of 17 consecutive patients that were submitted to AT-AMIC^®, between January of 2016 and April of 2017. Nine men and eight women, between 15 and 67 years were diagnosed with OLTs with the typical history of deep ankle pain and corresponding magnetic resonance imaging injury. Surgery was proposed only after failure of conservative treatment of at least 3 months. Patients answered the AOFAS score preoperatively and at the last follow-up, ranging from 8 to 20 months.

RESULTS

Average size of OLTs were 1.16cm², with Raikin 4 location being the most common (71%). Calcaneal osteotomy was the most common associated procedure, with 18%. Average follow-up was 10.8 months. Average AOFAS before surgery was 46.4, increasing to 89.5 at the last follow-up. This difference was statistically significant with a p-value of <0.001. No complications were observed and no changes in the post-operative protocol were needed.

CONCLUSION

AT-AMIC^® is a reliable and reproducible method of treatment for OLTs, reaching high clinical postoperative scores, with a very low rate of complications. Further comparative study is needed to prove its efficacy.

All-arthroscopic AMIC® (AT-AMIC®) technique with autologous bone graft for talar osteochondral defects: clinical and radiological results

PURPOSE

Autologous Matrix-Induced Chondrogenesis (AMIC^®) is known to provide satisfactory clinical results for the treatment of knee, hip, and ankle cartilage lesions. The purpose of this study was to evaluate clinical and radiological outcomes of patients treated with a new all-arthroscopic AMIC^® (AT-AMIC^®) technique with autologous bone graft for talar osteochondral defects at a follow-up of 24 months.

METHODS

Twenty patients underwent the AT-AMIC^® procedure and autologous bone graft for type III and IV talar osteochondral lesions. Patients were evaluated pre-operatively and at 6, 12, and 24 months post-operatively using the American Orthopedic Foot and Ankle Society (AOFAS) score, the visual analog scale, and the SF-12 (Short Form-12). Radiological assessment included computed tomography (CT), magnetic resonance imaging (MRI), and magnetic resonance observation of cartilage repair tissue (MOCART).

RESULTS

All scores significantly improved (p < 0.05) with respect to pre-operative values after 6 months. Further improvements were detected at 24 months (AOFAS, from 57.1 ± 14.9 before surgery to 86.6 ± 10.9 after 24 months; VAS, from 8.1 ± 1.4 to 2.5 ± 2.2; SF-12, from 29.9 ± 4.1 to 48.5 ± 6.9 and from 43.8 ± 2.9 to 53.1 ± 3.9, respectively, for Physical and Mental component score). Lesion area significantly reduced from 111.1 ± 43.2 mm² pre-operatively to 76.9 ± 38.1 mm² (p < 0.05) at final follow-up as assessed by CT, and from 154.1 ± 93.6 to 94.3 ± 61.3 mm² (p < 0.05) as assessed by MRI. The mean MOCART score was 42.8 ± 23.5 points and 50.9 ± 24.9 points, respectively, at 12 and 24 months after surgery (p < 0.05).

CONCLUSIONS

AT-AMIC^® with autologous bone grafting has proven to be a safe and effective minimal invasive technique, able to rapidly and significantly improve pain, function, and radiological healing of osteochondral talar lesions, with progressive further improvements up to 24 months. Orthopedic surgeons specialized in foot and ankle surgery should adopt the AT-AMIC^® technique for the treatment of osteochondral talar lesions, which proved to be effective and minimally invasive, avoiding malleolar osteotomy with a low risk of complications.

LEVEL OF EVIDENCE

IV.

Knee donor-site morbidity after mosaicplasty - a systematic review

BACKGROUND

Mosaicplasty has been associated with good short- to long-term results. Nevertheless, the osteochondral harvesting is restricted to the donor-site area available and it may lead to significant donor-site morbidity.

PURPOSE

Provide an overview of donor-site morbidity associated with harvesting of osteochondral plugs from the knee joint in mosaicplasty procedure.

METHODS

Comprehensive search using Pubmed, Cochrane Library, SPORTDiscus and CINAHL databases was carried out through 10th October of 2016. As inclusion criteria, all English-language studies that assessed the knee donor-site morbidity after mosaicplasty were accepted. The outcomes were the description and rate of knee donor-site morbidity, sample's and cartilage defect's characterization and mosaicplasty-related features. Correlation between mosaicplasty features and rate of morbidity was performed. The methodological and reporting quality were assessed according to Coleman's methodology score.

RESULTS

Twenty-one studies were included, comprising a total of 1726 patients, with 1473 and 268 knee and ankle cartilage defects were included. The defect size ranged from 0.85 cm2 to 4.9 cm2 and most commonly 3 or less plugs (averaging 2.9 to 9.4 mm) were used. Donor-site for osteochondral harvesting included margins of the femoral trochlea (condyles), intercondylar notch, patellofemoral joint and upper tibio-fibular joint. Mean donor-site morbidity was 5.9 % and 19.6 % for knee and ankle mosaicplasty procedures, respectively. Concerning knee-to-knee mosaicplasty procedures, the most common donor-site morbidity complaints were patellofemoral disturbances (22 %) and crepitation (31 %), and in knee-to-ankle procedures there was a clear tendency for pain or instability during daily living or sports activities (44 %), followed by patellofemoral disturbances, knee stiffness and persistent pain (13 % each). There was no significant correlation between rate of donor-site morbidity and size of the defect, number and size of the plugs (p > 0.05).

CONCLUSIONS

Osteochondral harvesting in mosaicplasty often results in considerable donor-site morbidity. The donor-site morbidity for knee-to-ankle (16.9 %) was greater than knee-to-knee (5.9 %) mosaicplasty procedures, without any significant correlation between rate of donor-site morbidity and size of the defect, number and size of the plugs. Lack or imcomplete of donor-site morbidity reporting within the mosaicplasty studies is a concern that should be addressed in future studies.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I-IV studies.

Osteochondral transplantation of autologous graft for the treatment of osteochondral lesions of talus: 5- to 7-year follow-up

PURPOSE

Bone marrow stimulation procedures (microfractures/drilling) are considered the gold standard for the primary treatment of osteochondral talar lesions. In the literature, there is lack of evidence about the appropriate treatment in cases of failure of these procedures. A technique of osteochondral autologous transplantation of talar graft was used. It was hypothesized that this is a successful method with good results and low complication rates. Additionally, a technique of anterior ankle approach with temporary removal of a bone block from the distal tibia that gives adequate access to posterior talar dome lesions is demonstrated.

METHODS

Between 2004 and 2007, 46 patients (37 males, 9 females), with OLT for which arthroscopic treatment with curettage and drilling or microfracture had failed, underwent osteochondral transplantation with an osteochondral graft harvested from the ipsilateral talar articular facet. A medial malleolar osteotomy or a distal tibial wedge osteotomy was used to access the talar dome defect.

RESULTS

The median follow-up time was 5.5 years (range 52-75 m). Thirty-four lesions (70.8 %) were located in the central talar dome in the coronal plane, while 26 (54.1 %) and 19 (39.5 %) lesions were located in the lateral and medial aspect of talar dome in saggital plane, respectively. The overall improvement between the preoperative and post-operative AOFAS and VAS FA score was 35 points (p < 0.001) and 39 points (p < 0.001), respectively. Clinical results were considered as good in 43 patients (93.4 %) and fair in three patients (6.5 %). All the transplanted grafts were observed to incorporate fully into the recipient bed. No complications occurred at the site of the malleolus osteotomy or tibial osteotomy and the donor site at the talus.

CONCLUSIONS

The midterm results suggest that the technique of osteochondral transplantation of autologous talar graft for osteochondral lesions of talus after failure of primary treatment with bone marrow stimulation can be safely and successfully used. It demonstrates excellent post-operative scores including improvement of pain and function. This procedure is combined with removal of a tibial bone block and its subsequent replacement and does not yield complications experienced with other procedures.

LEVEL OF EVIDENCE

Retrospective case series, Level IV.

Medial malleolar osteotomy for the treatment of talar osteochondral lesions: anatomical and morbidity considerations

PURPOSE

Osteochondral lesions of the talus are often located posteromedially requiring open surgery to facilitate solid and complete osteochondral reconstruction. The aim of the study was to identify the optimal anatomical site for medial malleolar osteotomy based on the criteria of minimal cartilage damage (Study I) and to report on the morbidity in patients receiving osteotomy performed at the previously identified site (Study II).

METHODS

For Study I, cartilage coverage of the tibiofibular ankle joint facet was measured in 40 cadaveric ankles (20 cadaver specimens). In Study II, we assessed clinical (VAS pain score, AOFAS score, range of motion) and radiological outcome measures (SPECT-CT) in 17 patients (mean age, 36.8 ± 10.8 years) undergoing medial malleolar osteotomy.

RESULTS

The medial edge in the transition zone of the tibial plafond to the medial malleolus showed less than 75 % of cartilage coverage in 62.5 % of cadavers (Study I). Surgery resulted in lower pain levels (2.4 ± 2.6 compared with 6.3 ± 1.8 points; p < 0.001) and greater AOFAS scores (82.9 ± 14.1 compared with 43.5 ± 10.8 to points; p < 0.001) compared with baseline (Study II). No signs of intra-operative damage or mal- or non-union were found. Long-term morbidity was found in one patient. Implant removal was necessary in 12 of 17 patients (71 %).

CONCLUSION

Anatomically, there is an optimal location for the medial malleolar osteotomy at the medial ankle edge involving minimal cartilage damage. Clinical results using this location showed no short- or mid-term morbidity and little long-term morbidity. However, many patients required re-intervention for implant removal.

LEVEL OF EVIDENCE

IV.

Low Level of Evidence and Methodologic Quality of Clinical Outcome Studies on Cartilage Repair of the Ankle

PURPOSE

To examine the level of evidence and methodologic quality of studies reporting surgical treatments for osteochondral lesions of the ankle.

METHODS

A search was performed using the PubMed/Medline, Embase, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Cochrane databases for all studies in which the primary objective was to report the outcome after surgical treatment of osteochondral lesions of the ankle. Studies reporting outcomes of microfracture, bone marrow stimulation, autologous osteochondral transplantation, osteochondral allograft transplantation, and autologous chondrocyte implantation were the focus of this analysis because they are most commonly reported in the literature. Two independent investigators scored each study from 0 to 100 based on 10 criteria from the modified Coleman Methodology Score (CMS) and assigned a level of evidence using the criteria established by the Journal of Bone and Joint Surgery. Data were collected on the study type, year of publication, number of surgical procedures, mean follow-up, preoperative and postoperative American Orthopaedic Foot & Ankle Society score, measures used to assess outcome, geography, institution type, and conflict of interest.

RESULTS

Eighty-three studies reporting the results of 2,382 patients who underwent 2,425 surgical procedures for osteochondral lesions of the ankle met the inclusion criteria. Ninety percent of studies were of Level IV evidence. The mean CMS for all scored studies was 53.6 of 100, and 5 areas were identified as methodologically weak: study size, type of study, description of postoperative rehabilitation, procedure for assessing outcome, and description of the selection process. There was no significant difference between the CMS and the type of surgical technique (P = .1411). A statistically significant patient-weighted correlation was found between the CMS and the level of evidence (r = -0.28, P = .0072). There was no statistically significant patient-weighted correlation found between the CMS and the institution type (r = 0.05, P = .6480) or financial conflict of interest (r = -0.16, P = .1256).

CONCLUSIONS

Most studies assessing the clinical outcomes of cartilage repair of the ankle are of a low level of evidence and of poor methodologic quality.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I through IV studies.

Anterolateral tibial osteotomy for accessing osteochondral lesions of the talus in autologous osteochondral transplantation: functional and t2 MRI analysis

BACKGROUND

Autologous osteochondral transplantation (AOT) is a primary treatment strategy for large or cystic osteochondral lesions of the talus (OLT) or a secondary replacement strategy after failed bone marrow stimulation. The technique requires perpendicular access to the talar dome, which is often difficult to obtain for posterior or lateral lesions. Traditional methods to access these areas have required disruption of the syndesmotic complex with concern over osteotomy reduction, malalignment, and ligament disruption. An alternate to these traditional methods of access is an anterolateral tibial osteotomy. The purpose of this study was to report functional and magnetic resonance imaging (MRI) outcomes in a series of patients that underwent AOT for treatment of an OLT via an anterolateral tibial osteotomy.

METHODS

Records of patients that underwent an anterolateral tibial osteotomy for AOT were retrospectively reviewed. Pre- and postoperative Foot and Ankle Outcome Scores (FAOS) and demographic data were recorded. Magnetic resonance observation of cartilage repair tissue (MOCART) was used to assess morphologic state of tibial cartilage at the repair site of the osteotomy. Quantitative T2 mapping MRI was analyzed in the superficial and deep cartilage layers of the repair site of the osteotomy and in adjacent normal cartilage to serve as control tissue. Seventeen patients with a mean age of 36.9 (range, 17-76) years underwent anterolateral tibial osteotomy with a mean follow-up of 64 (range, 29 to 108) months. MOCART data were available in 9 of 17 patients, and quantitative T2 mapping was available in 6 patients.

RESULTS

FAOS significantly improved from an average 39.2 (range, 14 to 66) out of 100 points preoperatively to 81.2 (range, 19 to 98) postoperatively (P < .01). The average MOCART score was 73.9 out of 100 points (range, 40 to 100). Quantitative T2 analysis demonstrated relaxation times that were not significantly different from the normal native cartilage in both the deep half and superficial half of interface repair tissue (P > .05).

CONCLUSION

This study demonstrated that the anterolateral tibial osteotomy was a reasonable alternative for accessing centrolateral or posterolateral OLT for AOT with limited morbidity associated with the osteotomy. The evidence demonstrated adequate osteotomy and cartilaginous healing with improvement in functional outcome scores at medium-term follow-up.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Branching patterns of the superficial peroneal nerve: implications for ankle arthroscopy and for anterolateral surgical approaches to the ankle

Ankle arthroscopic procedures offer less postoperative morbidity with faster healing times than open surgical procedures but still have associated risks. Complication rates as high as 17% have been reported. One of the most commonly reported complications is iatrogenic damage to the superficial peroneal nerve, which can result in numbness, tingling, or painful neuralgia. In the present study, we attempted to better assess the location of the superficial peroneal nerve at the ankle to improve preoperative planning and reduce complication rates. Fifty ankle specimens were dissected. A concerted effort was made to classify the location of the superficial peroneal nerve according to the Takao branching pattern, zones of the ankle, and distance to anatomic landmarks. Through our dissections, we found that most ankles have 2 nerve branches at the level of the ankle joint (Takao type II) and that the location of the superficial peroneal nerve branches at the ankle correlated directly with the ankle width. Additionally, 68% of specimens contained a nerve branch located in zone 1, where the anterolateral portal is placed, and 12% had a branch in zone 5, the location of the anteromedial portal site. The results of the present study have confirmed the wide variation in nerve location at the level of the ankle joint and serve to highlight the need for extreme caution during surgical procedures at the ankle.

Retrograde drilling of talar osteochondritis dissecans lesions: a feasibility and accuracy analysis of a novel electromagnetic navigation method versus a standard fluoroscopic method

PURPOSE

A novel method using an electromagnetic navigation system (ENS) was developed, and its feasibility and accuracy for retrograde drilling procedures were evaluated and compared with the standard freehand fluoroscopic method in an experimental setting.

METHODS

A controlled laboratory study of 16 standard freehand fluoroscopically guided and 16 electromagnetically navigated retrograde drilling procedures was performed on 4 cadaveric human ankle joints. Four artificial cartilage lesions were consecutively set, 2 on the medial and 2 on the lateral talar dome. Drilling accuracy was measured in terms of the distance from the final position of the drill bit to the tip of the probe hook and the distance between the tip of the drill bit and the center of the cartilage lesion on the articular cartilage surface. Intraoperative fluoroscopy exposure times were documented, as were readjustments of drilling directions or complete restarts. All procedures were timed with a stopwatch.

RESULTS

Successful retrograde drilling was accomplished in 12 cases with the standard fluoroscopy-guided technique and in all 16 ENS-guided procedures. The overall mean time for the fluoroscopy-guided procedures was 660.00 ± 239.87 seconds and the overall mean time for the ENS method was 308.06 ± 54.03 seconds, providing a mean time benefit of 420.13 seconds. The mean distance from the final position of the drill bit to the tip of the probe hook was 3.25 ± 1.29 mm for the standard method and 2.19 ± 0.54 mm for the ENS method, and the mean distance between the tip of the drill bit and the center of the cartilage lesion on the articular cartilage surface was 2.50 ± 0.97 mm for the standard method and 0.88 ± 0.81 mm for the ENS method.

CONCLUSIONS

Compared with the standard fluoroscopic technique, the ENS method used in this study showed higher accuracy and a shorter procedure time and required no X-ray radiation.

CLINICAL RELEVANCE

The novel method considerably improves on the standard operating procedure in terms of safety, operation time, and radiation exposure.

Effect of implantation accuracy on ankle contact mechanics with a metallic focal resurfacing implant

BACKGROUND

Talar osteochondral defects can lead to joint degeneration. Focal resurfacing with a metallic implant has shown promise in other joints. We studied the effect of implantation accuracy on ankle contact mechanics after focal resurfacing of a defect in the talar dome.

METHODS

Static loading of seven cadaver ankles was performed before and after creation of a 15-mm-diameter osteochondral defect on the talar dome, and joint contact stresses were measured. The defect was then resurfaced with a metallic implant, with use of a custom implant-bone interface fixture that allowed fine control (in 0.25-mm steps) of implantation height. Stress measurements were repeated at heights of -0.5 to +0.5 mm relative to an as-implanted reference. Finite element analysis was used to determine the effect of implant height, post axis rotation, and valgus/varus tilt over a motion duty cycle.

RESULTS

With the untreated defect, there was a 20% reduction in contact area and a 40% increase in peak contact stress, as well as a shift in the location of the most highly loaded region, as compared with the values in the intact condition. Resurfacing led to recovery of 90% of the contact area that had been measured in the intact specimen, but the peak contact stresses remained elevated. With the implant 0.25 mm proud, peak contact stress was 220% of that in the intact specimen. The results of the finite element analyses agreed closely with those of the experiments and additionally showed substantial variations in defect influences on contact stresses across the motion arc. Talar internal/external rotations also differed for the unfilled defect. Focal implant resurfacing substantially restored kinematics but did not restore the stresses to the levels in the intact specimens.

CONCLUSIONS

Focal resurfacing with a metallic implant appears to have the potential to restore normal joint mechanics in ankles with a large talar osteochondral defect. However, contact stresses were found to be highly sensitive to implant positioning.

Osteochondral lesions of the talus: retrograde drilling with high-field-strength MR guidance

The institutional review board approved the use of cadaveric specimens, and informed consent was obtained from all volunteers. The authors performed and assessed a magnetic resonance (MR)-assisted navigation method for minimally invasive retrograde drilling of talar osteochondral lesions. For this method, a single imaging plane is sufficient for navigation during intervention. To accomplish this objective, a passive MR navigation device was used to evaluate 16 cadaveric ankle joints. Use of this interactive MR-assisted navigation method in combination with a passive aiming device allowed precise and rapid retrograde drilling of talar osteochondral lesions.

Talonavicular joint approach to the talar body: a cadaver study

BACKGROUND

Lesions of the talar dome or tumors within the talar body may require an open approach with medial or lateral malleolar osteotomies. The aim of this study was to evaluate the possibility and feasibility of a new minimally invasive approach without osteotomy, using the talonavicular joint (TJ) as the entry portal for lesions of the talar body.

MATERIALS AND METHODS

Nine cadaveric feet were used for this study. Using the TJ and a 5-mm skin incision we aimed to reach the superolateral, superomedial, inferolateral and inferomedial corners of the talar body under fluoroscopy. A 2-mm Kirshner wire and a 4-mm cannulated drill bit were used to reach the desired target area and an angled curette was used for curettage after reaching the target. The proximity of vascular structures to the entry portal was noted. The talar and navicular joint surfaces were checked for any damage. The articular areas of the talar heads and the defect areas were measured.

RESULTS

All 4 targets and even the posterior talus could be reached by this approach. The nearest neurovascular structures were the saphenous vein and the saphenous nerve. The navicular cartilage was not damaged in any specimen. The talar defect area corresponded to only 3.3% of the talar head cartilaginous area.

CONCLUSION

The TJ approach can be used to reach lesions in all regions of the talar body without the need for an osteotomy. A mini-incision may be used to retract the saphenous nerve and vein. Damage to the talar head cartilage is minimal with this approach which requires no special equipments.

CLINICAL RELEVANCE

This study shows that talar dome lesions can be reached with a minimally invasive method.

Autologous chondrocyte implantation in chondral defects of the knee with a type I/III collagen membrane: a prospective study with a 3-year follow-up

PURPOSE

The clinical results after autologous chondrocyte implantation (ACI) with a collagen membrane using sequential objective patient evaluation (clinical examination and magnetic resonance imaging [MRI]) are inadequately reported. This prospective study was performed to determine the results after ACI at different time intervals over a period of 36 months.

METHODS

Between 2000 and 2002, 63 patients (mean age, 34 years) with full-thickness chondral lesions of the knee underwent an autologous chondrocyte implantation and were evaluated preoperatively and at 6, 18, and 36 months after surgery. The chondrocyte suspension within the defect was covered with a type I/III collagen membrane. Depending on the localization of the defects (femoral condyles, trochlea, and retropatellar), the patients were assigned to three different groups. Exclusion criteria were meniscal pathologies, axial malpositioning, and ligament instabilities. Baseline clinical scores (modified Cincinnati knee score and the International Cartilage Repair Society score) were determined and compared with follow-up data by using the paired Wilcoxon test.

RESULTS

The ICRS and modified Cincinnati score showed significant improvement (P < .01) in all time intervals between preoperative and 6, 18, and 36 months after surgery. There was no significant difference in the final outcome between different defect localizations (P > .2). The Pearson coefficient of correlation between clinical and MRI scores was 0.73 and significant at the 0.01 level. There was no patient with a symptomatic graft hypertrophy.

CONCLUSIONS

ACI is an effective method in the treatment of isolated cartilage defects in the knee. Graft hypertrophy can be avoided by using a collagen membrane. Significant improvement (P < .001) occurs still between 18 and 36 months after surgery.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Results after microfracture of full-thickness chondral defects in different compartments in the knee

OBJECTIVE

To determine if the clinical results after microfracture of full-thickness cartilage lesions deteriorate over a period of 36 months.

METHODS

Between 1999 and 2002 85 patients (mean age 39.5 years) with full-thickness cartilage lesions underwent the microfracture procedure and were evaluated preoperatively and 6, 18 and 36 months after surgery. Exclusion criteria were meniscal pathologies, axial malpositioning and ligament instabilities. Baseline clinical scores were compared with follow-up data by paired Wilcoxon-tests for the modified Cincinnati knee and the International Cartilage Repair Society (ICRS)-score. The effects of the lesion localization and Magnetic resonance imaging (MRI) parameters were evaluated using the Pearson correlation and independent samples tests.

RESULTS

Both scores revealed significant improvement 18 months after microfracture (P<0.0001). Within the second 18 months after surgery there was a significant deterioration in the ICRS-score (P<0.0001). The best results could be observed in chondral lesions of the femoral condyles. Defects in other areas of the knee deteriorated between 18 and 36 months after microfracture. MRI 36 months after surgery revealed best defect filling in lesions on the femoral condyles with significant difference in the other areas (P<0.02). The Pearson coefficient of correlation between defect filling and ICRS-score was 0.84 and significant at the 0.01 level.

CONCLUSIONS

Microfracture is a minimal invasive method with good short-term results in the treatment of small cartilage defects. A deterioration of the results starts 18 months after surgery and is most evident in the ICRS-score. The best prognostic factors have young patients with defects on the femoral condyles.