Surgical procedures in patients with haemophilic arthropathy of the ankle.

BACKGROUND: In haemophilia, the ankle joint is one of the most common and earliest joints affected by recurrent bleeding, commonly resulting in end-stage ankle osteoarthritis during early adulthood. The surgical treatment of haemophilic ankle arthropathy is challenging. PURPOSE: This review aims to highlight the literature addressing clinical outcomes following the most common approaches for different stages of haemophilia-induced ankle osteoarthritis: arthroscopic debridement, joint distraction arthroplasty, supramalleolar osteotomies, total ankle replacement, and ankle arthrodesis. METHODS: A systematic literature review was performed using established medical literature databases. The following information was retrieved from the literature: patients' demographics, surgical technique, duration of follow-up, clinical outcome including pain relief and complication rate. RESULTS: A total of 42 clinical studies published between 1978 and 2015 were included in the systematic literature review. Eight and 34 studies had prospective and retrospective design, respectively. The most common studies were level IV studies (64.3%). DISCUSSION: The orthopaedic treatment of patients with haemophilic ankle osteoarthritis is often challenging and requires complete and careful preoperative assessment. In general, both joint-preserving and joint non-preserving procedure types can be performed. All specific relative and absolute contraindications should be considered to achieve appropriate postoperative outcomes. CONCLUSION: The current literature demonstrated that orthopaedic surgeries, with appropriate indication, in patients with haemophilic ankle arthropathy result in good postoperative results comparable to those observed in non-haemophiliacs. The surgical treatment should be performed in a setting with the ability to have multidisciplinary management, including expertise in haematology.

Subchondral bone remodeling is related to clinical improvement after joint distraction in the treatment of ankle osteoarthritis.

OBJECTIVE: In osteoarthritis (OA), subchondral bone changes alter the joint's mechanical environment and potentially influence progression of cartilage degeneration. Joint distraction as a treatment for OA has been shown to provide pain relief and functional improvement through mechanisms that are not well understood. This study evaluated whether subchondral bone remodeling was associated with clinical improvement in OA patients treated with joint distraction. METHOD: Twenty-six patients with advanced post-traumatic ankle OA were treated with joint distraction for 3 months using an Ilizarov frame in a referral center. Primary outcome measure was bone density change analyzed on computed tomography (CT) scans. Longitudinal, manually segmented CT datasets for a given patient were brought into a common spatial alignment. Changes in bone density (Hounsfield Units (HU), relative to baseline) were calculated at the weight-bearing region, extending subchondrally to a depth of 8mm. Clinical outcome was assessed using the ankle OA scale. RESULTS: Baseline scans demonstrated subchondral sclerosis with local cysts. At 1 and 2 years of follow-up, an overall decrease in bone density (-23% and -21%, respectively) was observed. Interestingly, density in originally low-density (cystic) areas increased. Joint distraction resulted in a decrease in pain (from 60 to 35, scale of 100) and functional deficit (from 67 to 36). Improvements in clinical outcomes were best correlated with disappearance of low-density (cystic) areas (r=0.69). CONCLUSIONS: Treatment of advanced post-traumatic ankle OA with 3 months of joint distraction resulted in bone density normalization that was associated with clinical improvement.

[Aseptic loosening of total ankle replacement : One-stage revision ankle arthroplasty]. / Aseptische Lockerung einer OSG­Endoprothese : Einzeitiger Prothesenwechsel.

OBJECTIVE: To revise one or both loosened prosthesis components, to achieve postoperative pain relief, and preserve ankle range of motion. INDICATIONS: Aseptic loosening of the tibial and/or talar ankle prosthesis components without substantial bone defect of the tibial or talar bone stock. CONTRAINDICATIONS: General surgical or anesthesiological risks, infections, critical soft tissue conditions, nonmanageable hindfoot instability, neurovascular impairment of the lower extremity, neuroarthropathy (e. g. Charcot arthropathy), substantial nonreconstructable osseous defects with or without cysts on the tibial and/or talar side, non-compliance, patients with primary total ankle replacement (TAR) using intramedullary fixation (stem fixation), patients with severely reduced bone quality, insulin-dependent diabetes mellitus, smoking, unrealistic patient expectations, patients with high activity in sports. SURGICAL TECHNIQUE: Exposure of the ankle joint using the previous incision (anterior or lateral transfibular approach). Mobilization and removal of loosened prosthesis component. Careful debridement of bone stock at bone-prosthesis interface. Determination of prosthesis component size. Implantation of definitive prosthesis components. Wound closure in layers. POSTOPERATIVE MANAGEMENT: A soft wound dressing is used. Thromboprophylaxis is recommended. Patient mobilization starts at postoperative day 1 with 15 kg partial weight bearing using a stabilizing walking boot or cast for 6 weeks. Following clinical and radiographic follow-up at 6 weeks, full weight bearing is initiated gradually. RESULTS: Between January 2007 and December 2012 a one-stage revision TAR was performed in 14 patients with a mean age of 52.7 ± 12.0 years (29.8-70.5 years). The indication for revision surgery was aseptic loosening of one or both prosthesis components. The mean time between the initial TAR and revision surgery was 5.9 ± 2.9 years (2.0-11.5 years). In 2 patients a tibiotalocalcaneal arthrodesis was performed due to painful aseptic loosening of revision TAR. In all patients a significant pain relief was observed.

The effect of accuracy of implantation on range of movement of the Scandinavian Total Ankle Replacement.

When performing the Scandinavian Total Ankle Replacement (STAR), the positioning of the talar component and the selection of mobile-bearing thickness are critical. A biomechanical experiment was undertaken to establish the effects of these variables on the range of movement (ROM) of the ankle. Six cadaver ankles containing a specially-modified STAR prosthesis were subjected to ROM determination, under weight-bearing conditions, while monitoring the strain in the peri-ankle ligaments. Each specimen was tested with the talar component positions in neutral, as well as 3 and 6 mm of anterior and posterior displacement. The sequence was repeated with an anatomical bearing thickness, as well as at 2 mm reduced and increased thicknesses. The movement limits were defined as 10% strain in any ligament, bearing lift-off from the talar component or limitations of the hardware. Both anterior talar component displacement and bearing thickness reduction caused a decrease in plantar flexion, which was associated with bearing lift-off. With increased bearing thickness, posterior displacement of the talar component decreased plantar flexion, whereas anterior displacement decreased dorsiflexion.

The blood supply of the common peroneal nerve in the popliteal fossa.

We investigated the blood supply of the common peroneal nerve. Dissection of 19 lower limbs, including six with intra-vascular injection of latex, allowed gross and microscopic measurements to be made of the blood supply of the common peroneal nerve in the popliteal fossa. This showed that a long segment of the nerve in the vicinity of the fibular neck contained only a few intraneural vessels of fine calibre. By contrast, the tibial nerve received an abundant supply from a constant series of vessels arising directly from the popliteal and posterior tibial arteries. The susceptibility of the common peroneal nerve to injury from a variety of causes and its lack of response to operative treatment may be explained by the tenuous nature of its intrinsic blood supply.

Ankle fractures in patients with diabetes mellitus.

Diabetes mellitus is considered an indicator of poor prognosis for acute ankle fractures, but this risk may be specific to an identifiable subpopulation. We retrospectively reviewed 42 patients with both diabetes mellitus and an acute, closed, rotational ankle fracture. Patients were individually matched to controls by age, gender, fracture type, and surgical vs non-surgical treatment. Outcomes were major complications during the first six months of treatment. We contrasted secondarily 21 diabetic patients with and 21 without diabetic comorbidities. Diabetic patients and controls did not differ significantly in total complication rates. More diabetic patients required long-term bracing. Diabetic patients without comorbidities had complication rates equal to their controls. Diabetic patients with comorbidities had complications at a higher rate (ten patients; 47%) than matched controls (three patients; 14%, p = 0.034). A history of Charcot neuroarthropathy led to the highest rates of complication. An increased risk of complications in diabetic patients with closed rotational fractures of the ankle are specific to a subpopulation with identifiable related comorbidities.

Relationship between foot flexibility and urinary incontinence in nulliparous varsity athletes.

OBJECTIVE: To explore the relationship between urinary incontinence in elite nulliparous athletes and force absorption on impact, as assessed by foot arch flexibility. METHODS: One investigator measured medial longitudinal arch height in two gait stances (neutral and maximally dorsiflexed ankle positions) in 47 female varsity athletes representing five sports. Each athlete completed a questionnaire about urinary incontinence prevalence. We compared the change in arch height between the two gait stances with the prevalence of urinary incontinence. RESULTS: There was a statistically significant association between decreased foot flexibility and urinary incontinence; the mean percent change in arch height was 8.94 +/- 0.08% (standard deviation) in incontinent women and 13.70 +/- 0.09% in continent women (P = .03). CONCLUSION: How impact forces are absorbed may be one potential etiology for stress incontinence. An improved understanding of how impact forces are transmitted to the pelvic floor could provide important information about potential preventive interventions for urinary incontinence and other pelvic floor disorders, such as genital prolapse.

Effects of medial and lateral displacement calcaneal osteotomies on tibiotalar joint contact stresses.

Translational calcaneal osteotomies are used clinically to realign the mechanical axis of the lower limb. In this study, the effects of medial and lateral displacements of the posteroinferior fragment on tibiotalar joint contact mechanics were assessed using pressure-sensitive film. Eight osteotomized fresh-frozen cadaver specimens were loaded in each of three testing positions: neutral position (no shift), 1 cm of lateral displacement of the inferior fragment with respect to the superior fragment, and 1 cm of medial displacement of the inferior fragment. For an applied load of 1,330 N, two times body weight, a 1 cm lateral displacement shifted the center of pressure an average of 1.06 mm laterally, whereas a 1 cm medial displacement shifted the center of pressure an average of 1.58 mm medially. While global contact parameters (contact area, spatial mean contact stress, and peak local contact stress) were not appreciably altered by osteotomy, regional contact parameters changed in a reproducible and statistically significant manner. Among four nominally equal-sized, parasagittally bounded cartilage zones, lateral displacements consistently unloaded the most medial zone and increased loading of the most lateral zone; medial calcaneal displacements had the converse effect. These cadaver results suggest that translational calcaneal osteotomies may be used clinically to partially offload focal areas of cartilage along the medial and lateral borders of the tibiotalar joint.

Challenging fractures of the foot and ankle.

The foot and ankle is one of the most imaged parts of the body. Although most plain radiographs reveal no bony injury, subtle fractures can be overlooked. Because it is important to detect these fractures at the time of injury, a review of the most commonly missed foot and ankle fractures is presented.

Retrospective review of eighteen patients who underwent transtibial amputation for intractable pain.

BACKGROUND: Amputations are rarely performed solely for pain relief because of concerns regarding the persistence of pain and disability after the procedure. The purpose of this study was to assess the outcome of below-the-knee amputations performed to relieve intractable foot and ankle pain. METHODS: A chart review was conducted to identify all below-the-knee amputations that had been performed for the treatment of chronic foot and ankle pain by three orthopaedic foot and ankle specialists at three institutions. The inclusion criteria included (1) intractable foot or ankle pain as the surgical indication, (2) failure of maximal medical therapy, (3) failure of prior surgical reconstruction, and (4) a minimum follow-up period of twenty-four months after below-the-knee amputation. Patients with diabetes mellitus, peripheral vascular occlusive disease, or peripheral neuropathy were excluded. Each participant completed a two-part questionnaire with regard to the levels of disability, function, pain, and recreational activity both before and after the amputation. RESULTS: Twenty patients met the inclusion criteria, and eighteen completed the study. The study group included four women and fourteen men who had an average age of forty-two years (range, twenty-six to sixty-one years) and were followed for an average of forty-one months (range, twenty-five to eighty-five months) after the amputation. When asked whether they would have the below-the-knee amputation done again under similar circumstances, sixteen patients said yes, one was unsure, and one said no. The same distribution was observed when the patients were asked whether they were satisfied with the outcome: sixteen said yes, one was unsure, and one said no. Disability, pain, and recreational status were assessed with a 10-cm visual analog scale. After the amputation, the patients reported a decrease in both pain frequency (with the average score improving from 9.8 to 1.7; p < 0.0001) and pain intensity (with the average score improving from 8.4 to 2.6; p < 0.0001). Ten patients discontinued the use of narcotics, and seven decreased the level and/or dosage. Three patients worked before the amputation, and eight worked after the amputation. The average walking distance increased from 0.3 to 0.8 mile (p = 0.0034). CONCLUSION: In selected patients, a below-the-knee amputation may be a good salvage procedure for intractable foot and ankle pain that is unresponsive to all medical and local surgical reconstructive techniques.

Long-term results following ankle arthrodesis for post-traumatic arthritis.

BACKGROUND: Ankle arthrodesis is considered by many to be the standard operative treatment for end-stage ankle arthritis; however, the long-term effect of ankle arthrodesis on other lower-extremity joints remains largely unknown. The purpose of this study was to perform a clinical and radiographic review to determine the effect of ankle arthrodesis on the development of osteoarthritis in other lower-extremity joints. METHODS: Twenty-three patients who had had an isolated ankle arthrodesis for the treatment of painful posttraumatic arthritis of the ankle were followed for a mean of twenty-two years (range, twelve to forty-four years) after the operation. Each completed standardized, self-reported outcome questionnaires (the Foot Function Index, Western Ontario and McMaster University Osteoarthritis Index [WOMAC], and Short Form-36 [SF-36]), was examined clinically by two of the investigators, and underwent complete radiographic examination of the knee, ankle, and foot bilaterally. The radiographic grade of osteoarthritis was determined for each joint, and the levels of overall activity limitation, pain, and disability were determined for each patient from the clinical findings and questionnaire information. RESULTS: Osteoarthritis of the ipsilateral subtalar (p<0.0001), talonavicular (p<0.0001), calcaneocuboid (p<0.0001), naviculocuneiform (p = 0.0012), tarsometatarsal (p = 0.0009), and first metatarsophalangeal joints (p = 0.0012) was consistently more severe than the osteoarthritis of those joints on the contralateral side. Osteoarthritis did not develop more frequently in the ipsilateral knee or lesser metatarsophalangeal joints than it did on the contralateral side. Significant differences between the two sides were found with regard to overall activity limitation (p<0.0001), pain (p<0.0001), and disability (p<0.0001), with the involved side consistently more symptomatic. CONCLUSIONS: To our knowledge, the present series represents the longest follow-up study of ankle arthrodesis to date. Our cohort of patients all had isolated post-traumatic ankle arthritis, and each underwent a successful isolated ankle arthrodesis. At a mean of twenty-two years, the majority of the patients had substantial, and accelerated, arthritic changes in the ipsilateral foot but not the knee. They were often limited functionally by foot pain. Although ankle arthrodesis may provide good early relief of pain, it is associated with premature deterioration of other joints of the foot and eventual arthritis, pain, and dysfunction.

Results of treatment of displaced patellar fractures by partial patellectomy.

The results of partial patellectomy as a treatment for displaced patellar fractures were assessed retrospectively with use of clinical, radiographic, and isokinetic strength-testing criteria. Forty patients who had been followed for an average of 8.4 years were studied. In the extremity that had been operated on, the mean active range of motion was 94 per cent, the circumference of the thigh was 100 per cent, and the strength of the quadriceps was 85 per cent of these measurements in the contralateral extremity. The over-all result was rated as excellent in twenty patients, good in eleven, fair in six, and poor in three. There was a significant statistical correlation between the type of fracture and the outcome. The results of this study indicate that partial patellectomy can be an effective treatment for selected patellar fractures.

Familial cervical dysplasia.

Nine of twelve family members from three generations were affected by an inherited form of cervical vertebral dysplasia. All of the affected people had an abnormality of the first cervical vertebra. Some also had defects of the axis and caudad to it. The mode of transmission of the disorder is autosomal dominant, with apparently complete penetrance and variable expressivity. Two patients had symptoms. One had a passively correctable tilt of the head, with an associated audible clunk and hypoplasia of the left superior facet of the second cervical vertebra. This patient had no local symptoms, neurological involvement, or muscle spasm. In the other patient, suboccipital pain developed. Radiographs revealed an anterior atlanto-occipital dislocation. The symptoms resolved after reduction and arthrodesis. Because of the apparently complete penetrance of this disorder, physicians caring for patients who have this type of congenital malformation of the cervical spine should consider examination of closely related members of the family. Clinical findings such as tilting of the head, torticollis, or limitation of cervical motion suggest that additional evaluation should be done. The examination should include lateral radiographs of the cervical spine in flexion and extension. Three-dimensional computed-tomography reformatting was helpful in demonstrating the complex cervical anatomy in our patients. Patients who have recognized abnormalities should be followed and should be re-examined whenever local or neurological symptoms develop. A magnetic resonance image of the spine in flexion and extension was valuable for identification of the potentially disastrous situation of impending damage to the cord in patients who had instability and evolving symptoms.

Total ankle arthroplasty: a unique design. Two to twelve-year follow-up.

We evaluated the intermediate-term results of a novel total ankle arthroplasty that includes insertion of the components without cement and arthrodesis of the tibiofibular syndesmosis as part of the operative procedure. One hundred consecutive Agility ankle replacements were performed in ninety-five patients between 1984 and 1993. At the time of follow-up, eighty-three patients (eighty-six ankles) were alive and twelve patients (fourteen ankles) had died. Five (6 per cent) of the eighty-six ankles in the living patients had been revised. Including the components that had been revised for loosening, twenty-one (twelve tibial and nine talar) components had migrated. Delayed union of the syndesmosis (twenty-eight ankles) and non-union of the syndesmosis (nine ankles) were associated with the development of lysis around the tibial component. Non-union of the syndesmosis was also associated with migration of the tibial component and circumferential radiolucency around that component. In addition to the patients who died, one patient had a resection of the implant with subsequent arthrodesis. The remaining eighty-two patients (eighty-five ankles) were the basis for the clinical evaluation in the study. The average age at the time of the procedure was sixty-three years (range, twenty-seven to eighty-one years). At the time of the most recent follow-up (range, 2.8 to 12.3 years; average, 4.8 years), forty-seven (55 per cent) of the remaining eighty-five ankles were not painful and twenty-four (28 per cent) were only mildly painful. The range of motion of the fifty-six ankles that were examined at the time of follow-up averaged 36 degrees (range, 10 to 64 degrees), and the results for seventy-nine (93 per cent) of the eighty-five ankles were satisfactory to the patients.

Triple arthrodesis: twenty-five and forty-four-year average follow-up of the same patients.

BACKGROUND: Triple arthrodesis is used to treat major deformities of the hindfoot and is often performed in young patients. The purpose of this study was to assess the long-term outcomes of triple arthrodesis in young patients. METHODS: Sixty-seven feet of fifty-seven patients were evaluated at an average of twenty-five and forty-four years after triple arthrodesis. The most common indication for the operation was neuromuscular imbalance of the hindfoot, which was secondary to poliomyelitis in thirty-seven feet (55 percent), Charcot-Marie-Tooth disease in six (9 percent), spinal cord abnormalities in four (6 percent), cerebral palsy in three (4 percent), and Guillain-Barré syndrome in one (1 percent). RESULTS: Fifty-two feet (78 percent) had some residual deformity after the arthrodesis. However, these deformities appeared to be nonprogressive between 1973 and 1994. Pseudarthrosis occurred in thirteen feet. Thirty feet or ankles (45 percent) were painful at the first follow-up evaluation, and thirty-seven feet or ankles (55 percent) were painful at the second follow-up evaluation. Of the thirty feet or ankles that were painful at the first follow-up evaluation, twenty-three were painful at the second follow-up evaluation. Of the thirty-seven feet or ankles that were not painful at the first follow-up evaluation, fourteen were painful at the second follow-up evaluation. Eighteen patients (32 percent) needed walking support at the time of the first follow-up, and thirty-nine patients (68 percent) needed it at the time of the second follow-up. Two of the patients who needed support at the first follow-up evaluation did not need it at the second follow-up evaluation. At the first follow-up evaluation, twenty-one ankles (31 percent) had no radiographic evidence of degenerative changes. However, by the second follow-up evaluation, all of the ankles had some degenerative changes. Similar progressive arthritic findings were noted at the naviculocuneiform and tarsometatarsal joints. According to the system of Angus and Cowell, the overall result at the time of the first follow-up was rated as good in fifty feet (75 percent) and as fair in seventeen feet (25 percent). At the time of the second follow-up, nineteen feet (28 percent) were rated as good, forty-six (69 percent) were rated as fair, and two (3 percent) were rated as poor. CONCLUSIONS: Despite progressive symptoms and radiographic degeneration in the joints of the ankle and midfoot, fifty-four patients (95 percent) were satisfied with the result of the operation. The triple arthrodesis was a satisfactory solution for imbalance of the hindfoot in this group of patients.

The effect of foot structure on the three-dimensional kinematic coupling behavior of the leg and rear foot.

BACKGROUND AND PURPOSE: Differences in foot structures have been reported to account for the large variability in findings in previous studies that have examined the relationship between foot structure and the interdependent rotations of the lower extremity. The purpose of this study was to determine, in individuals with radiographically distinct foot structures, the effect of foot structure on three-dimensional kinematic behavior of the leg and rear foot during running. SUBJECTS AND METHODS: Based on radiographic measurements, 10 recreational runners were assigned to a low rear-foot group and another 10 recreational runners were assigned to a high rear-foot group. Three-dimensional kinematic data were collected during treadmill running. Individual axis rotations and the "coupled" relationship between the leg and rear-foot segments were defined using a Cardan angle system of three ordered rotations. RESULTS: The predominant rotations suggest a combined subtalar and talocalcaneal joint axis to favor calcaneal eversion and inversion for the low rear-foot group and tibial medial and lateral rotation for the high rear-foot group. Group differences were also found for the coupling ratio, which described the proportion of calcaneal eversion and inversion transferred or coupled to tibial axial rotation. CONCLUSION AND DISCUSSION: The rotational patterns and coupling response unique to each foot group may enhance our understanding of lower-extremity injuries related to certain foot structures. An assessment of the coupling relationship in combination with traditional frontal-plane measurements may better guide decisions regarding selection of footwear and orthoses.

Pattern of diabetic neuropathic arthropathy associated with the peripheral bone mineral density.

The relationship between the bone mineral density (BMD) and Charcot arthropathy is unclear. Prospectively, 55 consecutive diabetic patients presenting with a Charcot arthropathy of the foot or ankle were classified as having a fracture, dislocation, or a combination fracture-dislocation pattern of initial destruction. In these groups we used dual-energy x-ray absorptiometry to compare the peripheral bone of the affected and unaffected limbs. The clinical data relating to diabetes and related major comorbidities and the site of the arthropathy (ankle, hindfoot, midfoot, forefoot) were also compared. There were 23 patients with a fracture pattern, 23 with a dislocation pattern, and nine with a combination. The age-adjusted odds ratio for developing a Charcot joint with a fracture pattern as opposed to a dislocation pattern in patients with osteopenia was 9.5 (95% confidence interval 2.4 to 37.4; p = 0.0014). Groups also differed as to the site of the arthropathy. Fracture patterns predominated at the ankle and forefoot whereas dislocations did so in the midfoot. Diabetic Charcot arthropathy of the foot and ankle differs according to the pattern of the initial destruction. The fracture pattern is associated with peripheral deficiency of BMD. The dislocation pattern is associated with a normal BMD.

The compartments of the foot revisited. Rethinking the validity of cadaver infusion experiments.

Previous dye-infusion experiments on cadavers have suggested that the hindfoot should be divided into four muscle compartments including a newly described 'calcaneal' element containing quadratus plantae. Since there are no clinical data to support this proposed division, we re-examined the validity of the infusion experiment. We made infusions of dilute Omnipaque at a constant rate into flexor digitorum brevis of four cadaver feet. We monitored the spread of the infusate by real-time CT imaging and measured the pressures at the infusion site by side-ported needles. In all feet, the barrier between flexor digitorum brevis and quadratus plantae became incompetent at pressures of less than 10 mmHg. Pressure gradients in this range cannot be expected to affect tissue perfusion significantly and independently generate compartment syndromes. These results do not confirm those of previous studies carried out by uncontrolled and unmonitored injections made by hand. Injection studies in cadaver limbs can give dramatically different results depending upon the assumptions made when designing the experiment. The technique cannot adequately act as a model of the physiology of the compartment syndrome. As the existence of a physiologically significant compartmental boundary between flexor digitorum brevis and quadratus plantae is based solely on a cadaver infusion experiment the presence of a 'calcaneal' compartment has not been confirmed.

Compartmental divisions of the hand revisited. Rethinking the validity of cadaver infusion experiments.

The results of a cadaver dye-infusion experiment suggested that the hand has ten muscle compartments and that the volar interossei occupy a separate anatomical compartment from the adjacent dorsal interossei. This is not supported by clinical findings. With various minor modifications, we repeated the experiment, infusing Omnipaque into the second dorsal interosseus muscle of four cadaver hands. We used real-time CT imaging to monitor the spread of contrast medium and side-ported needles to measure compartmental pressures. In all four hands, the tissue barrier between dorsal and volar interossei became incompetent at pressures of less than 15 mmHg. Our data indicate that, although cadaver infusion studies can delineate potentially significant musculoskeletal barriers, their physiological relevance must be confirmed clinically.

Achilles tendon injuries.

As the number of persons who participate in athletic activity into their later years has increased, so has the incidence of overuse injuries to the Achilles tendon. The etiology of these problems is multifactorial and includes biomechanical factors and training errors. Use of a histopathologic scheme for classification of these injuries facilitates a logical approach to treatment. Conservative care is a mainstay of treatment for inflammatory conditions. Satisfactory outcomes may be obtained with either nonoperative or operative treatment of acute ruptures, although surgically treated patients appear to recover better functional capacity. Treatment of neglected injuries to the Achilles tendon continues to be a challenging problem.