Tendon Elongation and Function After Delayed or Standard Loading of Surgically Repaired Achilles Tendon Ruptures: A Randomized Controlled Trial.

BACKGROUND: Achilles tendon ruptures often result in long-term functional deficits despite accelerated (standard) rehabilitation. PURPOSE/HYPOTHESIS: The purpose of this study was to investigate if delayed loading would influence functional, clinical, and structural outcomes of the muscles and tendon 1 year after a surgical repair. It was hypothesized that delaying the loading would reduce the heel-rise height deficit 1 year after Achilles tendon rupture. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: In total, 48 patients with a surgically repaired Achilles tendon rupture were randomized to 2 groups: the standard group received the currently accepted rehabilitation, and the delayed group received the same rehabilitation except that initial loading was delayed by 6 weeks. The primary outcome was the heel-rise height difference between the injured and uninjured sides at 1 year. The secondary outcomes were (1) tendon length measured with magnetic resonance imaging, (2) muscle fascicle length and pennation angle of the gastrocnemius medialis muscle, (3) Doppler activity measured with ultrasonography, (4) Achilles tendon Total Rupture Score (ATRS), and (5) isometric muscle strength. RESULTS: The mean heel-rise height deficits for the standard and delayed groups were -2.2 cm and -2.1 cm, respectively (P = .719). The soleus part of the tendon was already elongated 1 week after surgery in both groups without a between-group difference (side-to-side difference: standard, 16.3 mm; delayed, 17.5 mm; P = .997) and did not change over 52 weeks. The gastrocnemius tendon length was unchanged at 1 week but elongated over time without a between-group difference (side-to-side difference at 52 weeks: standard, 10.5 mm; delayed, 13.0 mm; P = .899). The delayed group had less Doppler activity at 12 weeks (P = .006) and a better ATRS (standard, 60 points; delayed, 72 points; P = .032) at 52 weeks. CONCLUSION: Delayed loading was not superior to standard loading in reducing the heel-rise height difference at 1 year. The data indirectly suggested reduced inflammation in the initial months and a better patient-reported outcome at 1 year in the delayed group. The soleus part of the tendon was already markedly elongated (35%) 1 week after surgery, while the length of the gastrocnemius tendon was unchanged at 1 week but was 6% elongated at 1 year. Together, these data indirectly suggest that the delayed group fared better, although this finding needs to be confirmed in future investigations. REGISTRATION: NCT04263493 (ClinicalTrials.gov identifier).

Combined anterior cruciate ligament revision with reconstruction of the antero-lateral ligament does not improve outcome at 2-year follow-up compared to isolated acl revision; a randomized controlled trial.

PURPOSE: It is essential to obtain rotational stability of the knee after anterior cruciate ligament reconstruction (ACL-R) and it is suggested that a supplementary reconstruction of the antero-lateral ligament (ALL-R) may supports this. Theoretically, ALL-R may be particularly advantageous to support revision of failed ACL-Rs. It was hypothesized that ACL revision combined with ALL-R will result in superior outcome compared to isolated ACL revision. METHODS: The study was designed as a randomized controlled trial. Patients eligible for first time ACL revision were randomized to either isolated ACL revision (- ALL group) or ACL revision combined with a single-stranded allograft ALL-reconstruction (+ ALL group). Patient reported outcomes and function were evaluated at two-year follow-up by KNEES-ACL, KOOS, and Tegner activity scale. Objective knee laxity was evaluated at one-year follow-up using an instrumented Rolimeter test, the pivot shift test, and a manual Lachman test. RESULTS: A total of 103 patients were enrolled with 49 patients randomized to the + ALL group and 54 patients in the - ALL group. There were no differences at baseline between groups regarding age, gender, body mass index, preoperative patient reported outcome scores and concomitant meniscus or cartilage injury. The ACL revision was performed with an allograft in 10 patients (20%) in the + ALL group and 8 patients (15%) in the -ALL group. At follow-up there was no significant difference between the groups in patient reported outcome scores and clinical knee laxity. CONCLUSION: Supplementary ALL-R does not improve subjective outcome of first time ACL revision at two-years and clinical knee stability at one-year follow-up compared to isolated ACL revision. LEVEL OF EVIDENCE: Level I.

High degree of consensus amongst an expert panel regarding focal resurfacing of chondral and osteochondral lesions of the femur with mini-implants.

INTRODUCTION: The rationale for the use of mini-implants for partial resurfacing in the treatment of femoral chondral and osteochondral lesions is still under debate. The evidence supporting best practise guidelines is based on studies with low-level evidence. A consensus group of experts was convened to collaboratively advance towards consensus opinions regarding the best available evidence. The purpose of this article is to report the resulting consensus statements. METHODS: Twenty-five experts participated in a process based on the Delphi method of achieving consensus. Questions and statements were drafted via an online survey of two rounds, for initial agreement and comments on the proposed statements. An in-person meeting between the panellists was organised during the 2022 ESSKA congress to further discuss and debate each of the statements. A final agreement was made via a final online survey a few days later. The strength of consensus was characterised as: consensus, 51-74% agreement; strong consensus, 75-99% agreement; unanimous, 100% agreement. RESULTS: Statements were developed in the fields of patient assessment and indications, surgical considerations and postoperative care. Between the 25 statements that were discussed by this working group, 18 achieved unanimous, whilst 7 strong consensus. CONCLUSION: The consensus statements, derived from experts in the field, represent guidelines to assist clinicians in decision-making for the appropriate use of mini-implants for partial resurfacing in the treatment of femoral chondral and osteochondral lesions. LEVEL OF EVIDENCE: Level V.

The Effect of Endoscopic Partial Plantar Fasciotomy on Morphologic and Functional Properties of the Foot.

BACKGROUND: The lifetime risk of plantar fasciitis is 10%, and operative treatment in the form of endoscopic partial plantar fascia release are often performed in cases refractory for nonsurgical treatment. The effect of the operation on the biomechanical properties of the foot has only been sparsely studied. METHODS: This is a prospective, observational study of 25 patients with plantar fasciitis, for a minimum of 3 months, verified by ultrasonographic scanning, who had endoscopic partial fasciotomy. A bony spur was resected if present. At the calcaneal insertion, the medial half of the central band of the plantar fascia was excised in full thickness. The biomechanical properties of the foot were evaluated before surgery and 12 months postoperatively. RESULTS: Foot length increased 0.17 cm (P = .03), the width of the central zone 0.35 cm (P = .019), the modified arch index 0.05 (P = .032), and the Foot Posture Index 1.0 (P = .0014). There were no significant changes in rearfoot eversion angle, ankle dorsiflexion and jump distance, or in magnetic resonance imaging-measured 3D navicular position from pre- to postoperation, with or without loading, and no changes in ultrasonographically measured heel pad thickness. A tantalum bead (0.7-mm-diameter) was inserted during operation into the most proximal part of the released medial plantar fascia. Radiographs obtained few days postoperatively and 1 year later revealed no changes in the tantalum-calcaneus distance in supine position, but an increase from 48.3 to 50.7 mm (P = .045) in one-leg standing, suggesting a higher flexibility of the remaining fascia. Patients with a body mass index above and below 27.0 demonstrated no significant differences in any of the assessments at 12 months. CONCLUSION: There were minimal changes in the measured foot morphologic and functional properties at 1-year follow-up, after endoscopic partial plantar fascia release. LEVEL OF EVIDENCE: Level II, prospective cohort study.

Loss of the knee-ankle coupling and unrecognized elongation in Achilles tendon rupture: effects of differential elongation of the gastrocnemius tendon.

PURPOSE: The biarticular anatomy of the gastrocnemii is an important mechanism of knee-ankle coupling and differential elongation may affect this function leading to weakness of the push-off phase during the gait. Achilles tendon ruptures may cause detachment of the gastrocnemius tendon from the soleus aponeurosis with subsequent differential elongation of the individual subtendons. This study investigated the effects of such detachment by investigating tendon fusion levels of the two muscle groups, and the effect of sequential differential elongation of the gastrocnemius on the Achilles tendon resting angle (ATRA) and to the knee-ankle coupling. METHODS: Conjoined tendon length (CTL) was measured in 23 cadavers. ATRA in knee extension (ATRA 0) and 90-degree knee flexion (ATRA 90) was measured with the gastrocnemius tendons (GT) intact, transected and with the gap reduced in 5-mm increments. In 15 specimens, knee-ankle coupling was examined. RESULTS: Considerable anatomical variation was present with CTL ranging from 2 to 40% of fibular length. In the intact triceps, surae ATRA 0 differed from ATRA 90 by 6 degrees (p < 0.001). Cutting the gastrocnemius caused an immediate separation of the tendon ends by 19 mm. ATRA 0 and ATRA 90 increased 8 and 4 degrees (p < 0.001), significantly larger increase for ATRA 0 (p < 0.001). Lengthening the gastrocnemius 10 mm altered the coupling point 10 degrees towards dorsiflexion. Transfixing the gastrocnemius at the level of the gap where the Achilles was sectioned, decoupled the knee-ankle coupling in all but two specimens. A moderate correlation between CTL and length of the medial gastrocnemius tendon was found. CONCLUSIONS: A greater relative ATRA 0 than relative ATRA 90 indicates differential elongation of the gastrocnemius. By elongating the gastrocnemius the knee-ankle coupling point shifts dorsally, and 20 mm elongation completely decouples the knee-ankle coupling. Independent lengthening of the gastrocnemius may explain the loss of power experienced by some patients following acute Achilles tendon rupture despite what would appear to be appropriate approximation of the ruptured tendon ends. Recognizing this occurrence is crucial when treating Achilles tendon ruptures and such patients require surgical correction in order to avoid long-term weakness of push-off strength.

Patient-specific metal implants for focal chondral and osteochondral lesions in the knee; excellent clinical results at 2 years.

PURPOSE: Surgical treatment options for the management of focal chondral and osteochondral lesions in the knee include biological solutions and focal metal implants. A treatment gap exists for patients with lesions not suitable for arthroplasty or biologic repair or who have failed prior cartilage repair surgery. This study reports on the early clinical and functional outcomes in patients undergoing treatment with an individualised mini-metal implant for an isolated focal chondral defect in the knee. METHODS: Open-label, multicentre, non-randomised, non-comparative retrospective observational analysis of prospectively collected clinical data in a consecutive series of 80 patients undergoing knee reconstruction with the Episealer® implant. Knee injury and Osteoarthritis Outcome Score (KOOS) and VAS scores, were recorded preoperatively and at 3 months, 1 year, and 2 years postoperatively. RESULTS: Seventy-five patients were evaluated at a minimum 24 months following implantation. Two patients had undergone revision (2.5%), 1 declined participation, and 2 had not completed the full data requirements, leaving 75 of the 80 with complete data for analysis. All 5 KOOS domain mean scores were significantly improved at 1 and 2 years (p < 0.001-0.002). Mean preoperative aggregated KOOS4 of 35 (95% CI 33.5-37.5) improved to 57 (95% CI 54.5-60.2) and 59 (95% CI 55.7-61.6) at 12 and 24 months respectively (p < 0.05). Mean VAS score improved from 63 (95% CI 56.0-68.1) preoperatively to 32 (95% CI 24.4-38.3) at 24 months. The improvement exceeded the minimal clinically important difference (MCID) and this improvement was maintained over time. Location of defect and history of previous cartilage repair did not significantly affect the outcome (p > 0.05). CONCLUSION: The study suggests that at 2 years, Episealer® implants are safe with a low failure rate of 2.5% and result in clinically significant improvement. Individualised mini-metal implants with appropriate accurate guides for implantation appear to have a place in the management of focal femoral chondral and osteochondral defects in the knee. LEVEL OF EVIDENCE: IV.

Reconstruction of the anterior cruciate- and anterolateral ligament deficient knee with a modified iliotibial graft reduces instability more than with an intra-articular hamstring graft.

PURPOSE: To compare knee kinematics before and after anterior cruciate ligament ACL reconstruction (ACL-R) using hamstring graft (HG) and a double-stranded iliotibial tract graft attached to Gerdy's tubercle (providing an extra-articular anterolateral tenodesis) (named the modified iliotibial tract graft = MIT). METHOD: Eighteen cadaveric knees were tested in a 6 degree of freedom kinematics rig. An optical tracking system recorded kinematics of the knee from 0 to 80 degrees of flexion applying no load, internal/external rotation (IR/ER), valgus/varus rotation (VGR/VRR), simulated pivot shift (SPS), anterior translation (AT) and posterior translation loads. The knee was tested before and after resection of the ACL and the anterolateral ligament (ALL), respectively; then after HG-ACL-R and MIT-ACL-R. Grafts were fixed at 20° of flexion. Results were compared to the intact knee. RESULTS: ACL resection resulted in a significant increase in AT (p < 0.05) over the entire range of motion, peaking at 20° of flexion, mean difference 6.6 ± 2.25 mm (p = 0.0007). ACL-R with HG-ACL and MIT-ACL restored AT. Resection of the ALL increased IR in the fully extended knee, mean difference 2.4 ± 2.1° (p = 0.024). When compared to the intact knee and the knee after HG-ACL-R, MIT-ACL-R knee reduced IR/SPS significantly (p < 0.05) in deep flexion angles (60°-80°), peaking at 80° of flexion. The MIT-ACL-R caused significantly less VRR at 80° flexion (p = 0.02). CONCLUSION: MIT-ACL-R restored AT equally to the HG-ACL-R. The MIT-ACL-R reduced IR and SPS in deep flexion, resulting in overconstraint. MIT-ACL-R can be used as an alternative to standard reconstruction methods.

Endoscopic fasciotomy for plantar fasciitis provides superior results when compared to a controlled non-operative treatment protocol: a randomized controlled trial.

PURPOSE: Plantar fasciitis is a frequent and painful condition with a lifetime incidence of 10%. Good results have been reported for operative treatment of plantar fasciitis refractory to non-surgical interventions in uncontrolled studies. The aim of this study was to compare the results of operative treatment (endoscopic debridement, removal of the heel spur and partial resection of the plantar fascia) with those of a controlled and supervised non-operative rehabilitation program. METHODS: Thirty consecutive patients with plantar fasciitis during more than 3 months were randomized to either (1) non-operative treatment with corticosteroid injections and a controlled strength training program or (2) an endoscopic 2-incision operation with partial fasciotomy and heel spur removal followed by the same strength training program. Patients were evaluated at entry and 3, 6, 12 and 24 months post-operatively with the foot function index (FFI) and pain score during activity on a 100 mm VAS scale (VAS activity). FFI at 6 and 12 months was defined a priori as primary endpoint. RESULTS: Both groups improved significantly over time. The FFI score was significantly better in the operated group compared to the non-surgically treated group 12 months post-operatively (p = 0.033), at 24 months this was, however, not significant (p = 0.06). VAS activity at 24 months was significantly (p = 0.001) in favor of the operative group. More patients returned to running and jumping in the operative group (p = 0.04). CONCLUSION: This randomized controlled trial found significant and clinically relevant superior results for the operative treatment of plantar fasciitis as measured by Foot Function Index at 1 year and by VAS activity at 2-year follow-up when compared to the results of a supervised rehabilitation program. LEVEL OF EVIDENCE: I.

[Younger patients with hip joint pain].

This review summarises the present knowledge of diagnosing and treating hip joint pain. The results of joint preserving surgery are good in symptomatic patients with hip dysplasia, acetabular retroversion or impingement (cam or pincer) without signs of osteoarthritis. Confirmation of intraarticular pathology as the cause of symptoms is established clinically, and the pathology can in many cases be visualised by a standing, standardised radiograph of the pelvis, which is the basis for admission to the relevant orthopaedic department. We present an algorithm for this. Dysplasia and retroversion can be treated by periacetabular osteotomy and impingement by arthroscopic procedures.

Plantar fasciitis treated with endoscopic partial plantar fasciotomy-One-year clinical and ultrasonographic follow-up.

BACKGROUND: Endoscopic operations for plantar fasciitis generally have good clinical outcome. The aim of this study was to record the effect of endoscopic partial fasciotomy and heel spur removal and evaluate by ultrasonography whether the fascia regenerates and the heel spur reforms. METHODS: Eleven consecutive patients were evaluated before and 3, 6 and 12 months after surgery. Operations were performed endoscopically using a deep fascial approach with a medial and a lateral portal. Bony spurs were removed and the medial half of the plantar fascia was transected. All patients followed a standardized rehabilitation program. RESULTS: Median Foot Function Index values decreased from 119 pre-surgery to 69 and 12 (p=0.004), at 3 months and 1year post-operatively respectively. Median VAS-score for first step pain was likewise reduced from median 71mm to 29mm and 7mm (p=0.004), respectively. Median fascial thickness at the medial insertion was 6.0mm (range 4.6-6.8mm) pre-operatively. A heel spur was present in 9 cases. One year postoperatively a well-defined fascia in the area of resection was demonstrated in 8 cases. In the rest of the cases scar tissue made it impossible to clearly outline the fascia. Nine of the feet showed good medial fascial tensioning. There was no evidence of recurrence of the bony spur. CONCLUSIONS: Endoscopic partial plantar fascia resection reduced pain symptoms and increased function significantly 3 months after operation, with additional effect achieved 12 months after surgery. Based on ultrasonography the resected fascia regenerated/healed, and a calcaneal spur did not recur.

Arthroscopic subacromial decompression results in normal shoulder function after two years in less than 50% of patients.

INTRODUCTION: The aim of this study was to evaluate the outcome two years after arthroscopic subacromial decompression using the Western Ontario Rotator-Cuff (WORC) index and a diagram-based questionnaire to self-assess active shoulder range of motion (ROM). METHODS: Outcomes in 80 patients with impingement of the shoulder undergoing arthroscopic subacromial decompression were prospectively assessed preoperatively, at three months and at two years post-operatively using the WORC index. All patients had received non-operative treatment for at least six months before undergoing surgery. Active range of motion was measured preoperatively by the examining physician and at two years by the patient him-/herself using a diagram-based questionnaire to self-assess active shoulder ROM. A total of 75 patients (94%), of whom 31 were women, completed the study. The median age was 56 years. In all, 31 patients had additional resection of the acromioclavicular joint. RESULTS: WORC scores improved significantly from preoperatively (median: 1,392) to three months (median: 204) and two years post-operatively (median: 243) (p < 0.001). A clinically significant decrease in the WORC index was observed in 83% of patients, but only 45% reported near normal or normal WORC scores, and 56% presented with a reduced active ROM at two years. CONCLUSION: Arthroscopic subacromial decompression -appears effective in alleviating symptoms in patients with subacromial impingement who are resistant to conservative treatment, but can only be expected to restore normal shoulder function as measured by the WORC in less than 50% of the cases. FUNDING: not relevant. TRIAL REGISTRATION: not relevant.

Iliotibial band autograft versus bone-patella-tendon-bone autograft, a possible alternative for ACL reconstruction: a 15-year prospective randomized controlled trial.

PURPOSE: The long-term results after using the iliotibial band autograft (ITB) in anterior cruciate ligament (ACL) reconstruction are not fully known. If equal in quality to conventional methods, the ITB graft could be a useful alternative as a primary graft, in revision surgery or multi-ligament reconstruction. The purpose is to assess whether the ITB autograft is a long-term reliable alternative to the bone-patella-tendon-bone (BPTB) autograft, using a prospective randomized controlled trial design. METHODS: From 1995 to 1996, sixty patients scheduled for primary ACL reconstruction were included in a prospective randomized controlled trial. Three senior knee surgeons, experienced in both types of ACL surgery, performed all the operations. A standardized and supervised rehabilitation programme was used for both groups for 6 months. Thirty patients received the ITB reconstruction, and 30 received the BPTB reconstruction. Forty-nine participated at follow-up in 2010 (82%). Primary outcome was the failure rate after ACL reconstruction. Secondary outcomes were knee injury osteoarthritis outcome score (KOOS) [pain, symptoms, Sport/Rec, quality of life (QOL), daily living function], Tegner activity scale, anterior knee pain-score, Lysholm score, Rolimeter laxity, extension deficit, single hop and crossover hop for distance. RESULTS: At 15-year follow-up, no significant difference existed between the groups. Graft failure occurred in 4 ITB subjects (16%) and 3 BPTB subjects (13%). KOOS (Sport/Rec) for the ITB group was 75 and 73 for the BPTB group. The KOOS (QOL) was 72 and 68 for the ITB group and BPTB group, respectively. CONCLUSION: Similar graft failure rates and KOOS were found when comparing ITB- and BPTB-operated individuals, at 15-year follow-up. The ITB graft had equal long-term clinical results compared to the BPTB graft and is recommended as a reliable alternative autograft for ACL reconstruction. LEVEL OF EVIDENCE: Therapeutic studies, Level I.

[Osteoid osteoma in the hip of 12-year-old girl]. / Osteoidt osteom i hoften hos en 12-årig pige.

Osteoid osteoma is a benign skeletal tumour most commonly located in the cortex of long bones and easily diagnosed with distinct symptoms and radiographic appearance. The less common peri-articular location presents a diagnostic difficulty due to its non-specific symptoms and the absence of radiological findings in the early state. This often leads to a delay in the final diagnosis and treatment. A case review of a young girl diagnosed with periarticular osteoid osteoma of the acetabulum is reported.

[Ultrasound in the diagnosis and treatment of developmental dysplasia of the hip. Evaluation of a selective screening procedure]. / Ultralydskanning ved diagnostik og behandling af hoftedysplasi. Vurdering af en selektiv screeningsprocedure.

INTRODUCTION: With the intention of reducing the treatment frequency of Developmental Dysplasia of the Hip (DDH), two hospitals in Copenhagen implemented a screening and treatment procedure based on selective referral to ultrasonography of the hip (US). This paper describes and evaluates the procedure. MATERIALS AND METHODS: The procedure defines procedures for referral, diagnosis, treatment and follow-up of DDH. From 1998 to 2003 children with risk factors or with positive Ortolanis or Barlows test were referred to US. RESULTS: The treatment rate was 0.47%, and the rate of late diagnosed cases 0.03%. No relationship was seen between morphological parameters at the first US and the outcome of hips classified as minor dysplastic or not fully developed (NFD). A statistically significant relationship was seen between the degree of dysplasia and the time until US normalization of the hips (p= 0.02). There was no relapse of dysplasia after treatment. The median duration of treatment was six, eight and nine weeks for mild, moderate and severe dysplasia respectively. CONCLUSION: The procedure resulted in a low rate of treatment and a small number of late diagnosed cases. Prediction of the outcome of minor dysplastic/NFD hips must be based on a minimum of two US. An individualization of the treatment length was possible, and treatment length could be shortened in many cases. Compared with the incidence of DDH in Gentofte Hospital before the use of US, we suggest that this selective ultrasound screening procedure is worthwhile.

[Treatment of patellofemoral arthritis with patello-femoral arthroplasties]. / Behandling af patellofemoral artrose med en patellofemoral alloplastik.

INTRODUCTION: Patellofemoral arthritis is a common entity and patellofemoral arthroplasties have been performed since the 1970s. However, follow-up studies are few, and the optimal indication for the operation has yet to be established. This study concentrates on the gains in patient-reported quality of life parameters achieved by the operation. MATERIAL AND METHODS: Of 26 patients operated with 31 Richards Model Patella II patellofemoral arthroplasties, 17 patients with 20 arthroplasties were available for clinical review using two subjective/objective scoring systems and one patient administered self evaluation form median 7.7 years after the operation. RESULTS: The revision rate for the prosthesis was low (3%). A frequency of short-term complications of 15% and of later surgical procedures of 20% was observed. The American Knee Society Score showed 65% excellent or good, 20% fair and 35% poor results. The results of the patient administered KOOS showed significant improvements for the subcategories ''symptoms'', ''pain", ''activities of daily living" and ''quality of life". The worst results were seen among patients with pre-arthritic patellofemoral pain syndrome. CONCLUSION: 7-8 years after patellofemoral arthroplasty survival of the prosthesis is good. The clinical result is unpredictable. Most patients can expect a reduction in their level of pain and a higher level of daily living activities. The level of sports and recreational activities did not increase, even among younger patients. Patients with patellofemoral pain before radiological signs of arthritis are present in the joint cannot expect a measurable effect from the operation.

Ankle eversion torque response to sudden ankle inversion Torque response in unbraced, braced, and pre-activated situations.

In 13 young ankle stable subjects, ankle eversion torque and peroneal EMG were simultaneously recorded in response to sudden ankle inversion. The eversion torque response was bi-phasic. The initial development of torque, which was responsible for 30% of the maximal eversion torque response, was observed 135 ms after the start of platform rotation and correlated well with the onset of the automatic postural peroneal EMG response. The remaining eversion torque response commenced after 305 ms, strongly correlating with the onset of the peroneal long latency voluntary EMG activity. With the ankle unbraced, 66% of the maximal torque level was reached in 326 ms. While braced, the same torque magnitude was reached using 230 ms (p<0.02), and pre-activation of the peroneal muscles allowed the subjects to reach the same level of torque in 89 ms (p<0.0005). Prior to the study, a common reaction pattern to sudden inversion was expected in an ankle stable population, but review of the eversion torque and EMG data from the 13 subjects revealed three different voluntary reaction patterns: 10 subjects showed an efficient activation of evertor muscles; two subjects stiffened their ankles with activation of both in- and evertor muscles; and one subject showed a marginal voluntary activation of the ankle evertors. The results of the study indicate that the reaction to sudden ankle inversion is not solely automatic. The main part of the torque response is voluntarily mediated and inter-individual differences in strategy seem to exist in healthy subjects.

Ultrasonography and articular cartilage defects in the knee: an in vitro evaluation of the accuracy of cartilage thickness and defect size assessment.

The purpose of this cadaver study was to test the accuracy of ultrasonography in measuring cartilage thickness, and the extent and depth of induced cartilage defects on the medial and lateral femoral condyles of the knee in a clinically relevant setting. With the knees maximally flexed, cartilage thickness was measured at 24 marked sites in four knees with a 10 MHz probe. The areas of measurement were then excised and the thickness measured with a calliper gauge. In another seven cadaver knees, 21 cartilage defects were produced. The defect diameter varied from 4 to 8 mm. The depths of the defects were either a partial cartilage defect (grade 2), a defect to intact subchondral bone (grade 3), or a defect involving subchondral bone (grade 4) (classification by ICRS). The limits of agreement between ultrasonography and calliper gauge measurement for cartilage thickness were chi(diff)+/-2SD(diff)=0.0+/-0.4 mm. For cartilage defect diameter, the limits of agreement between ultrasonography and the slide ruler measurement were chi(diff)+/-2SD(diff)=-0.2+/-1.0 mm. For the depths of the lesions there was a 100% agreement between radiologist and actual lesion depth for the classification into International Cartilage Repair Society (ICRS) grades 2, 3, and 4. Our conclusion is that ultrasonography is capable of measuring accurately both cartilage thickness and the extent and depth of induced cartilage defects in a cadaver model.

Inversion injury biomechanics in functional ankle instability: a cadaver study of simulated gait.

The purpose of this study was to test pathogenetic models for the "unprovoked" ankle inversion injuries seen in functional ankle unstable subjects. The consequence of spatial mal-alignment of the ankle/foot complex on the risk of producing an ankle inversion torque at heel-strike and during swing-phase follow through was analyzed in cadaver simulations. Heel-strike was simulated using a 5 degrees of freedom rig in a material testing machine. A set-up capable of accelerating lower limb specimens towards a support surface simulated swing-phase follow through. Joint excursions were monitored with flexible wire goniometers. The unloaded ankle/foot complex was placed in increasing positions of talar and subtalar joint excursions. The consequences of these settings on the behavior of the ankle/foot complex at heel-strike and when the lateral part of the foot "caught" the ground during swing-phase follow through were monitored. An inversion torque at heel-strike was first seen when the unloaded foot was set in positions exceeding 30 degrees of inversion combined with full plantar flexion and 10 degrees of internal tibial rotation. A collision between the lateral border of a 20 degrees inverted, but otherwise neutral ankle/foot complex and the ground surface during swing-phase follow through forced the foot into the full limit of inversion, plantar flexion and internal tibial rotation measurable in this set-up. Clinical consequence: The study showed that the foot/ankle complex exhibits a high degree of intrinsic stability at heel-strike. The foot will thus stabilize itself and move into normal eversion at the beginning of the stance-phase even though it is set to the ground in a substantial degree of mal-alignment. In contrast, the swing-phase collision model provides a link that can connect the small deficits in inversion angle awareness measured in chronic functional ankle unstable subjects with an increased risk in this group of sustaining ankle inversion injuries.

Factors Contributing to Chronic Ankle Instability: Kinesthesia and Joint Position Sense.

OBJECTIVE: To present a comprehensive review of the influence of altered kinesthesia and joint position sense on chronic ankle instability and to present a model connecting deficits in ankle position sense with the increased risk of sustaining lateral ankle sprains. DATA SOURCES: I searched MEDLINE for the years 1966-2001 using the key words ankle and kinesthesia or position sense and books on proprioception. DATA SYNTHESIS: Study findings suggest a risk for unprovoked lateral ankle sprains when the lateral border of the foot accidentally catches the ground surface during the late swing phase of normal locomotion. In normal situations, the lateral border of the foot clears the ground by only 5 mm, and a small increase in ankle-position error may substantially increase the risk of a collision. Findings of affected kinesthesia and joint position sense in subjects with chronically unstable ankles dominate over studies showing nonsignificant results, but the answer is far from clear. CONCLUSIONS/RECOMMENDATIONS: Changes in joint position sense and kinesthesia of a magnitude found in subjects with chronically unstable ankles can lead to an increased risk of sustaining lateral ankle sprains. Results from a small number of studies suggest that balance and coordination training can restore the increased uncertainty of joint positioning to normal levels.