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Dive into the research topics where Norman Espinosa is active.

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Featured researches published by Norman Espinosa.


Journal of Bone and Joint Surgery, American Volume | 2006

Latissimus dorsi transfer for the treatment of irreparable rotator cuff tears.

Christian Gerber; Gerardo Juan Maquieira; Norman Espinosa

BACKGROUND Treatment of irreparable rotator cuff tears remains controversial. Latissimus dorsi transfer to the greater tuberosity has been proposed for the treatment of irreparable tears associated with severe functional impairment and chronic, disabling pain. METHODS Sixty-seven patients with sixty-nine irreparable, full-thickness tears of at least two complete tendons were managed with latissimus dorsi transfer and were reviewed clinically and radiographically after an average of fifty-three months. The study group included fifty-two men and fifteen women, with an average age of sixty-one years. Thirteen patients also had deficient subscapularis function preoperatively. Outcome measures included the Constant and Murley score and the Subjective Shoulder Value. Osteoarthritis and acromiohumeral distance were measured on standardized radiographs. RESULTS The mean Subjective Shoulder Value increased from 28% preoperatively to 66% at the time of follow-up (p < 0.0001). The mean age and gender-matched Constant and Murley score improved from 55% to 73% (p < 0.0001). The pain score improved from 6 to 12 points (of a possible 15 points) (p < 0.0001). Flexion increased from 104 degrees to 123 degrees , abduction increased from 101 degrees to 119 degrees , and external rotation increased from 22 degrees to 29 degrees (p < 0.05). Abduction strength increased from 0.9 to 1.8 kg (p < 0.0001). There was a slight but significant increase in osteoarthritic changes (from stage 0.8 to stage 1.3; p = 0.0002). In shoulders with a negative preoperative lift-off test, significant improvements were observed in terms of both function and pain, and strength doubled from 1.0 to 2.0 kg (p = 0.0001), but osteoarthritic changes progressed from stage 0.7 to stage 1.1 (p = 0.0006). In shoulders with poor subscapularis function, no improvement in these parameters was observed. CONCLUSIONS Latissimus dorsi transfer durably and substantially improves chronically painful, dysfunctional shoulders with irreparable rotator cuff tears, especially if the subscapularis is intact. If subscapularis function is deficient, the procedure is of questionable benefit and probably should not be used.


Journal of Bone and Joint Surgery, American Volume | 2010

Misalignment of total ankle components can induce high joint contact pressures

Norman Espinosa; M. Walti; Philippe Favre; Jess G. Snedeker

BACKGROUND A major cause of the limited longevity of total ankle replacements is premature polyethylene component wear, which can be induced by high joint contact pressures. We implemented a computational model to parametrically explore the hypothesis that intercomponent positioning deviating from the manufacturers recommendations can result in pressure distributions that may predispose to wear of the polyethylene insert. We also investigated the hypothesis that a modern mobile-bearing design may be able to better compensate for imposed misalignments compared with an early two-component design. METHODS Two finite element models of total ankle replacement prostheses were built to quantify peak and average contact pressures on the polyethylene insert surfaces. Models were validated by biomechanical testing of the two implant designs with use of pressure-sensitive film. The validated models were configured to replicate three potential misalignments with the most CLINICAL RELEVANCE version of the tibial component, version of the talar component, and relative component rotation of the two-component design. The misalignments were simulated with use of the computer model with physiologically relevant boundary loads. RESULTS With use of the manufacturers guidelines for positioning of the two-component design, the predicted average joint contact pressures exceeded the yield stress of polyethylene (18 to 20 MPa). Pressure magnitudes increased as implant alignment was systematically deviated from this reference position. The three-component design showed lower-magnitude contact pressures in the standard position (<10 MPa) and was generally less sensitive to misalignment. Both implant systems were sensitive to version misalignment. CONCLUSIONS In the tested implants, a highly congruent mobile-bearing total ankle replacement design yields more evenly distributed and lower-magnitude joint contact pressures than a less congruent design. Although the mobile-bearing implant reduced susceptibility to aberrant joint contact characteristics that were induced by misalignment, predicted average contact stresses reached the yield stress of polyethylene for imposed version misalignments of >5 degrees.


Clinical Orthopaedics and Related Research | 2001

Arthroscopic treatment of shoulder stiffness.

Christian Gerber; Norman Espinosa; Thomas Georg Perren

The optimal treatment of shoulder stiffness remains controversial. The current authors reviewed the results of arthroscopic capsular release of 45 stiff shoulders in 45 patients that was done after the patients did not respond to conservative treatment. There were nine idiopathic frozen shoulders, 21 that had postoperative stiffness, and 15 shoulders with stiffness after trauma. At a mean followup of 26 months (minimum, 12 months), arthroscopic capsular release improved the subjective shoulder value from 25% to 68% and the age-and gender-adjusted Constant-Murley score from 41% to 75%. Pain improved from 4.7 to 10.9 of 15 points. Active, pain-free anterior elevation increased from 90° to 128° and external rotation increased from 14° to 31°. The quality of sleep improved from 0.5 to 1.6 on a two-point scale. The only improvement that did not reach statistical significance was the improvement in the ability to work. A retrospective analysis of the results stratified according to the etiology of stiffness showed that the outcome after treatment of idiopathic stiffness was better than after postoperative stiffness and that the results of treatment for posttraumatic stiffness were least favorable. The difference between preoperative state and followup, however, was not statistically significantly different from one group to another. All groups improved significantly and to a similar degree but the final outcome was related to the initial degree of disability. Arthroscopic release is an effective method for treatment of shoulder stiffness; however, the ultimate outcome is related directly to the severity of stiffness regardless of the etiology.


Foot & Ankle International | 2008

Current concept review: metatarsalgia.

Norman Espinosa; Ernesto Maceira; Mark S. Myerson

Metatarsalgia refers to localized or generalized forefoot pain in the region of the metatarsal heads.10 The term is frequently used as a “waste-basket” diagnosis for forefoot pain. Often this pain is plantar, beneath the metatarsal heads, and arises from either mechanical or iatrogenic causes.45 The surgical treatment of metatarsalgia remains controversial, with multiple procedures described in the literature.5,14,20,21,48 A thorough understanding of the biomechanics of the forefoot and the underlying pathology of the particular type of metatarsalgia affecting the patient is a prerequisite to selecting the proper treatment. This review focuses on central metatarsalgia, defined as pathology involving the second through fourth metatarsals. It will provide a basic understanding and classification of central metatarsalgia, and discuss the options for the successful management of this challenging clinical entity.


Foot & Ankle International | 2007

Hindfoot Instability in Cavovarus Deformity: Static and Dynamic Balancing

Patrick Vienne; Ralph Schöniger; Naeder Helmy; Norman Espinosa

Background: Chronic lateral ankle instability has been associated with varus deformity of the hindfoot, hyperactivity of the peroneus longus muscle, and insufficiency of the lateral ligaments. Many operative procedures have been described to correct this problem, but instability can recur if all contributing components are not treated. The purpose of this study was to offer an approach in the diagnosis and treatment of recurrent lateral ankle instability. Methods: Eight consecutive patients (nine feet) were treated for recurrent chronic lateral ankle instability. The average age at surgery was 25 (range 8 to 37) years. All patients had prior operative procedures that failed and had persistent pain and functional instability of the ankle joint. After clinical and radiographic examination, lateralizing calcaneal osteotomy to correct the structured varus deformity and peroneus longus to peroneus brevis tendon transfer to add dynamic correction were done in all patients. A Broström ligament reconstruction was added in four feet. All patients were evaluated clinically and radiographically at an average followup of 37 months. Preoperatively and postoperatively patients were evaluated by means of the American Orthopaedic Foot and Ankle Society (AOFAS) Score. Results: All patients were satisfied with the operation. The overall AOFAS-Score improved from 57 points preoperatively to 87 points postoperatively. Hindfoot alignment was restored to a valgus position at final evaluation. Conclusions: Recurrent chronic lateral ankle instability often is associated with chronic hindfoot malalignment and leads to functional impairment and patient discomfort. Clinical examination should determine the causes of instability. Varus malalignment of the hindfoot, hyperactivity of the peroneus longus muscle, and insufficiency of the lateral ligaments should be assessed and treated in a combined operative procedure to correct structured, static and dynamic components of the instability. The preliminary results of this particular approach are encouraging.


American Journal of Roentgenology | 2011

Hindfoot Alignment Measurements: Rotation-Stability of Measurement Techniques on Hindfoot Alignment View and Long Axial View Radiographs

Florian M. Buck; Adrienne Hoffmann; Nadja Mamisch-Saupe; Norman Espinosa; Donald Resnick; Juerg Hodler

OBJECTIVE The purpose of this article is to identify the most rotation-stable hindfoot alignment measurement techniques on hindfoot alignment view and long axial view radiographs. MATERIALS AND METHODS Hindfoot alignment was quantified on hindfoot alignment view and long axial view radiographs of a phantom in different rotation positions. Rotation stability of measurements using the calcaneal axis, the medial and lateral calcaneal contour, and the apparent moment arm were graphically compared. Interreader agreement was quantified using intraclass correlation coefficient. RESULTS On hindfoot alignment view radiographs, measurements using the medial and lateral calcaneal contour were rotation stable (± 5°). Measurements using the calcaneal axis were not reliable and showed considerable divergence with phantom rotation. Measurements using the apparent moment arm manifested an almost linear relationship to phantom rotation. On long axial view radiographs, all measurements manifested an almost linear relationship to phantom rotation, whereas those using the calcaneal axis were the most rotation stable. Interreader agreement of all measurement techniques was perfect on both hindfoot alignment and long axial view radiographs (intraclass correlation coefficient, 0.8-0.98; p < 0.001). Interreader agreement was slightly better on long axial view radiographs. CONCLUSION Hindfoot alignment measurements should be performed on hindfoot alignment view radiographs using the medial or lateral calcaneal contour or on long axial view radiographs using the calcaneal axis. Interreader agreement of hindfoot alignment measurements is slightly better on long axial view radiographs than on hindfoot alignment view radiographs.


Skeletal Radiology | 2010

Therapeutic impact of [18F]fluoride positron-emission tomography/computed tomography on patients with unclear foot pain

Dorothee R. Fischer; Gerardo Juan Maquieira; Norman Espinosa; Marco Zanetti; Rolf Hesselmann; Anass Johayem; Thomas F. Hany; Gustav K. von Schulthess; Klaus Strobel

PurposeTo evaluate the therapeutic impact of [18F]fluoride positron-emission tomography/computed tomography ([18F]fluoride PET/CT) imaging on patients with unclear foot pain.MethodsTwenty-eight patients were prospectively included in this study. Therapeutic management was defined by two experienced dedicated foot surgeons before and after [18F]fluoride PET/CT imaging. Twenty-six patients underwent cross-sectional imaging [CT, magnetic resonance (MR)] prior to PET/CT. A retrospective analysis of the magnetic resonance imaging (MRI) diagnoses was performed when a therapy change occurred after PET/CT imaging.ResultsIn 13/28 (46%) patients therapeutic management was changed due to PET/CT results. Management changes occurred in patients with the following diagnoses: os trigonum syndrome; sinus tarsi syndrome; os tibiale externum syndrome; osteoarthritis of several joints; non-consolidated fragments; calcaneo-navicular coalition; plantar fasciitis; insertional tendinopathy; suggestion of periostitis; neoarticulations between metatarsal bones. Os trigonum, os tibiale externum, subtalar osteoarthritis and plantar fasciitis were only seen to be active on PET/CT images but not on MR images.Conclusion[18F]fluoride PET/CT has a substantial therapeutic impact on management in patients with unclear foot pain.


Foot & Ankle International | 2013

Operative treatment of chronic irreparable Achilles tendon ruptures with large flexor hallucis longus tendon transfers.

Stefan Rahm; Christian Spross; Fabienne Gerber; Mazda Farshad; Florian M. Buck; Norman Espinosa

Background: Transfer of the flexor hallucis longus (FHL) tendon aims to restore function and relieve pain in chronic Achilles tendon (AT) disease. The goal of the present study was to investigate the clinical and radiographic outcomes of FHL transfer to the AT and to compare the transtendinous technique to the transosseous technique. We hypothesized that the type of technique would have a notable impact on outcome. Methods: Forty patients (42 ankles) were retrospectively reviewed and divided into group 1 (transtendinous technique, 22 patients/24 ankles) and group 2 (transosseous technique, 18 patients/18 ankles). Outcome parameters included the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score, Victorian Institute of Sports Assessment-Achilles (VISA-A) score, Foot Function Index (FFI), and Short Form-36 (SF-36) scores. Magnetic resonance imaging of the lower leg was performed preoperatively to assess muscle quality and fatty infiltration. Postoperatively, isokinetic plantar flexion strength was assessed using a Con-Trex dynamometer. Results: In group 1 (follow-up, 73 months; age, 52 years), the AOFAS score improved from 66 points to 89 points (P < .001) with average values for the VISA-A of 76 points, FFI-D pain 15%, and FFI-D function 22%. In group 2 (follow-up, 35 months; age, 56 years), the AOFAS score increased from 59 points to 85 points (P < .001) with mean values for the VISA-A 76 points, FFI-D pain 25%, and FFI-D function 24%. At follow-up, the average SF-36 score in group 1 was 66% and in group 2 was 77%. Isokinetic testing at 30 deg/s in group 1 revealed notable weakness in the operated ankle averaging 54.7 N·m (75% of normal), and in group 2 the average was 58.2 N·m (77% of normal). No statistically significant differences were found between the groups. Conclusion: The hypothesis was disproved. Both techniques for FHL transfer to AT, intratendinous and transosseous, provided good to excellent clinical and functional outcome in the treatment of irreparable AT disease. Level of Evidence: Level III, retrospective comparative series.


Foot & Ankle International | 2013

Posterior pilon fractures: a retrospective case series and proposed classification system.

Georg Klammer; Anish R. Kadakia; Joos D; Jeffrey D. Seybold; Norman Espinosa

Background: Posterior malleolus fractures occur in 7% to 44% of ankle fractures and are associated with worse clinical outcomes. Fractures that involve the posteromedial plafond extending to the medial malleolus have been described previously in small case series. Failure to identify this fracture pattern has led to poor clinical outcomes and persistent talar subluxation. The purpose of this study was to report our outcomes following fixation of this posterior pilon fracture and to describe a novel classification system to help guide operative planning and fixation. Methods: Eleven patients were identified following fixation of a posterior pilon fracture over a 4-year span; 7 returned at minimum 1-year follow-up to complete a physical examination, radiographs, and RAND-36 (health-related quality of life score developed at RAND [Research and Development Corporation] as part of the Medical Outcomes Study) and American Orthopaedic Foot & Ankle Society (AOFAS) ankle/hindfoot questionnaires. Patient records were reviewed to evaluate for secondary complications or operative procedures. Results: Our mean postoperative AOFAS ankle/hindfoot score was 82. Anatomical reduction of the plafond was noted radiographically in 7 of 11 patients, with the remainder demonstrating less than 2 mm of articular incongruity. Five of 7 patients demonstrated ankle and hindfoot range of motion within 5 degrees of the uninvolved extremity. Four complications required operative intervention; 2 patients reported continued pain secondary to development of CRPS. Conclusion: The posterior pilon fracture is a challenging fracture pattern to treat, and it has unique characteristics that require careful attention to operative technique. Our results following fixation of this fracture pattern are comparable with results in the literature. In addition, a novel classification scheme is described to guide recognition and treatment of this fracture pattern. Level of Evidence: Level IV, retrospective case series.


Foot and Ankle Clinics of North America | 2012

Biomechanics of the Normal and Arthritic Ankle Joint

Jess G. Snedeker; Stephan Wirth; Norman Espinosa

Understanding biomechanics of the normal and arthritic ankle joint can aid in analysis of an underlying clinical problem and provide a strategic basis for a more optimal management. The challenge to the clinician and the biomechanist is that the mechanical complexity of the ankle joint still clouds current understanding. This article provides an overview of current understanding of functional ankle anatomy, how this function can be altered in the degenerated ankle, and how surgical intervention further affects foot and ankle biomechanics. The focus is on how altered loading of neighboring joints in the midfoot and hindfoot may induce postoperative joint remodeling and can manifest in secondary clinical problems.

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