Mark S Muller

Hospital for Special Surgery, New York, New York, United States

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Publications (9)27.47 Total impact

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    ABSTRACT: Rupture of the proximal origin of the hamstrings leads to pain, weakness, and a debilitating decrease in physical activity. Repair of these injuries should be based on the expectation that these deficits can be addressed. The goal of this study was to objectively evaluate the efficacy of repair of proximal hamstring avulsions. Thirty-four patients were identified retrospectively to have a complete rupture of the proximal origin of the hamstrings based on the presence of a bowstring sign and the results of magnetic resonance imaging (MRI).Patients were contacted for follow-up evaluation to fill out a subjective questionnaire, to undergo functional testing, and to undergo isokinetic testing on a Cybex dynamometer. Twenty-three patients were evaluated. There were nine acute and fourteen chronic repairs, and the average period of follow-up was 43.3 months. Twenty-one of twenty-three patients reported returning to activity at an average of 95% of their pre-injury activity level at an average of 9.8 months. Eighteen patients reported excellent results; four, good results; and one, fair results. Hamstring strength was an average of 93% and 90% of that in the uninvolved limb at 240° per second and 180° per second, respectively. The hamstrings-to-quadriceps ratio was 56% for 240° per second and 48% at 180° per second. Hamstring endurance was an average of 81% and 91% of the nonoperative limb at 240° per second and 180° per second, respectively. Postoperative quadriceps strength and endurance were positively correlated with return to pre-injury level of activity (r = 0.6, p < 0.05; and r = 0.6, p < 0.05) and negatively correlated with time to return to sport (r = -0.5, p < 0.05; and r = -0.5, p < 0.05). There was no significant effect associated with age or time from injury. Repair of a symptomatic and displaced ruptured proximal hamstring tendon yields good subjective and objective functional results with minimal complications. Overall, patients are satisfied with surgical repair and experience return of functional activity with minimal postoperative weakness.
    The Journal of Bone and Joint Surgery 10/2011; 93(19):1819-26. DOI:10.2106/JBJS.J.01372 · 4.31 Impact Factor
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    ABSTRACT: Injuries in professional football players are common because of the nature of the collisions and the frequency of axial loading to the cervical spine. These injuries should be thoroughly evaluated because they can put the player at risk of future injury and even paralysis. The focus of this report is to present 2 cases of this injury and review the current body of literature. We present 2 cases of professional football players who experienced injuries to the lower posterior elements of their cervical spine simultaneously on a kickoff during a game. Both players described transient symptoms consistent with a "stinger," which is commonly encountered. Workup revealed fractures of the lower cervical spine in both patients. One patient was able to be managed conservatively and returned to football the following season. The second patient had an unstable fracture that ultimately required operative intervention, and the patient retired from professional football. Cervical spine injuries in football players need to be adequately evaluated, and in many cases can be career threatening. We recommend that players with persistent pain after a transient neurapraxia undergo radiography and computed tomography of the cervical spine to evaluate for a fracture.
    Neurosurgery 03/2011; 68(6):E1743-8; discussion E1748-9. DOI:10.1227/NEU.0b013e31821815af · 3.03 Impact Factor
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    ABSTRACT: This study evaluated different fibular-based reconstruction techniques for grade III posterolateral corner (PLC) injuries. Seven fresh-frozen cadaveric knees were used in this study. A surgical navigation system was used to determine varus opening and external rotation at 0 degrees , 30 degrees , and 60 degrees with a 9.8-Nm varus stress and 5-Nm external rotation stress applied to the tibia. Intact and disrupted PLC knees were used as controls. Four different fibular-based reconstruction techniques were evaluated. The femoral attachments consisted of a single- or double-tunnel technique, and the fibula attachment consisted of an anteroposterior or oblique tunnel technique. Sectioning of the PLC resulted in an increase in varus and external rotation at all flexion angles. All reconstruction techniques restored varus and external rotation stability compared with the PLC-deficient state, but the single-femoral tunnel reconstruction with an anteroposterior fibular tunnel did not restore varus or external rotation stability at 30 degrees and 60 degrees . No reconstruction technique overconstrained the knee at any flexion angle. A double femoral tunnel with an oblique fibular tunnel best restored native knee kinematics to the lateral side of the knee. Although there are many different techniques to reconstruct the PLC-deficient knee, this study suggests that a single-graft, fibular-based reconstruction that replicates the femoral insertions of the lateral collateral ligament and popliteus will be able to restore varus and external rotation stability to the knee.
    Arthroscopy The Journal of Arthroscopic and Related Surgery 08/2010; 26(8):1088-95. DOI:10.1016/j.arthro.2009.12.014 · 3.19 Impact Factor
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    ABSTRACT: Disruptions of the lateral soft tissue restraints of the elbow, including the lateral ulnar collateral ligament, are a well-recognized clinical entity which may result in chronic elbow instability. When symptomatic, most authors recommend surgery to reconstruct the LUCL. We report on a case of a professional football player who sustained complete disruption of the lateral collateral ligamentous complex from the lateral humeral epicondyle with extension of his injury into his common extensor origin. He was treated conservatively and returned to play after 4 weeks. Treatment algorithm and a review of the literature are discussed.
    HSS Journal 02/2010; 6(1):19-25. DOI:10.1007/s11420-009-9146-3
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    ABSTRACT: The purpose of this study was to determine the femoral and tibial fixation sites that would result in the most isometric MCL reconstruction technique. Seven cadaveric knees were used in this study. A navigation system was utilized to determine graft isometry continuously from 0 masculine to 90 masculine. Five points on the medial side of the femur and four on the tibia were tested. A graft positioned in the center of the MCL femoral attachment (F(C)) and attached in the center of the superficial MCL attachment on the tibia led to the best isometry (2.7 +/- 1.1 mm). Movement of the origin superiorly only 4 mm (F(S)) led to graft excursion of greater than 10 mm (P < 0.01). MCL reconstruction performed with the origin of the MCL within the femoral footprint and the insertion in tibial footprint of the superficial MCL results in the least graft excursion when the knee is cycled between 0 masculine and 90 masculine. Although the MCL often heals without surgical intervention, surgical reconstruction is occasionally in Grade III MCL and combined ligamentous injuries to the knee. This study demonstrates the optimal position of the MCL reconstruction to reproduce the kinematics of the native knee.
    Knee Surgery Sports Traumatology Arthroscopy 05/2009; 17(9):1078-82. DOI:10.1007/s00167-009-0805-1 · 2.84 Impact Factor
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    ABSTRACT: The medial collateral ligament is a broad ligament that functions as the primary stabilizer against valgus knee stress, particularly at 30 degrees of flexion. A double-bundle reconstruction technique that better restores the native medial collateral ligament anatomy will restore valgus and external rotation stability to a medial collateral ligament-deficient knee. Controlled laboratory study. Seven fresh-frozen cadaveric knees were studied. A surgical navigation system was used to determine valgus opening and external rotation at 0 degrees and 30 degrees with a 9.8-N.m valgus stress applied to the tibia graft isometry at multiple points on the tibia and femur. Intact and disrupted medial collateral ligament knees were used as controls. Four repair techniques were tested: Bosworth, modified Bosworth, anatomical single bundle, and anatomical double bundle. Complete sectioning of the medial collateral ligament resulted in an increase in valgus opening of 5 degrees at 0 degrees and 7.7 degrees at 30 degrees . External rotation increased 4.6 degrees at 0 degrees and 9.7 degrees at 30 degrees . Single-bundle techniques (Bosworth, anatomical single bundle) did not restore valgus laxity at 0 degrees or 30 degrees ; the anatomical single bundle did not restore external rotation at 0 degrees . Double-bundle techniques (modified Bosworth, anatomical double bundle) restored valgus laxity and external rotation to the native knee conditions at 0 degrees and 30 degrees . At 30 degrees , the modified Bosworth was 0.3 degrees tighter and the anatomical double bundle 0.2 degrees tighter than was the intact knee. The center of the medial collateral ligament origin on the femur to the proximal insertion of the superficial medial collateral ligament resulted in the most isometric graft position. Medial collateral ligament reconstruction configurations that use a double-bundle reconstruction better resist valgus and external rotations in response to valgus stress than do single-bundle techniques. Although the medial collateral ligament often heals without surgical intervention, surgical reconstruction is occasionally necessary in grade III medial collateral ligament and combined ligamentous injuries to the knee. Double-bundle reconstruction of the medial collateral ligament better resists valgus forces across the knee and may allow for better surgical outcome after medial collateral ligament reconstruction.
    The American Journal of Sports Medicine 04/2009; 37(6):1123-30. DOI:10.1177/0363546508331134 · 4.70 Impact Factor
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    ABSTRACT: Anterior cruciate ligament reconstruction has become one of the most common arthroscopic knee procedures, and it has excellent success rates. Intraoperative technical complications are uncommon but can be devastating to knee function. Each of the multiple steps in the reconstruction has associated complications.
    Instructional course lectures 02/2009; 58:355-75.
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    ABSTRACT: Injuries to the hip account for approximately 10% of all injuries in football, but definitive diagnosis is often challenging. Although these injuries are often uncomplicated contusions or strains, intra-articular lesions are increasingly found to be sources of hip pain. The objective was to define the incidence and etiologic factors of intra- and extra-articular hip injuries in the National Football League (NFL). Descriptive epidemiology study. The NFL Injury Surveillance System was used to define all hip-related injuries from 1997 to 2006. Injuries were included if the athlete missed more than 2 days. All hip and groin injuries were included for evaluation. The authors also report on NFL players with intra-articular injuries seen at their institution outside of the NFL Injury Surveillance System. There were a total of 23 806 injuries from 1997 to 2006, of which 738 were hip injuries (3.1%) with an average of 12.3 days lost per injury. Muscle strains were the most common injury. Intra-articular injuries resulted in the most time lost. Contact injuries most likely resulted in a contusion, and noncontact injuries most often resulted in a muscle strain. In the authors' institutional experience, many of the athletes with labral tears have persistent adductor strains that do not improve despite adequate therapy. Hip injuries represent a small but substantial percentage of injuries that occur in the NFL. A majority of these injuries are minor, with a return to play within 2 weeks. Intra-articular injuries are more serious and result in a significant loss of playing time. The "sports hip triad" (labral tear, adductor strain, and rectus strain) is described as a common injury pattern in the elite athlete.
    The American Journal of Sports Medicine 11/2008; 36(11):2187-95. DOI:10.1177/0363546508319898 · 4.70 Impact Factor
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    ABSTRACT: Football is one of the leading causes of athletic-related injuries. Injury rates and patterns of the training camp period of the National Football League are unknown. Injury rates will vary with time, and injury patterns will differ between training camp practices and preseason games. Descriptive epidemiology study. From 1998 to 2007, injury data were collected from 1 National Football League team during its training camp period. Injuries were recorded as a strain, sprain, concussion, contusion, fracture/dislocation, or other injury. The injury was further categorized by location on the body. Injury rates were determined based on the exposure of an athlete to a game or practice event. An athlete exposure was defined as 1 athlete participating in 1 practice or game. The injury rate was calculated as the ratio of injuries per 1000 athlete exposures. There were 72.8 (range, 58-109) injuries per year during training camp. Injuries were more common during weeks 1 and 2 than during weeks 3 to 5. The rate of injury was significantly higher during games (64.7/1000 athlete exposures) than practices (12.7/1000 athlete exposures, P < .01). The rate of season-ending injuries was also much higher in games (5.4/1000 athlete exposures) than practices (0.4/1000 athlete exposures). The most common injury during the training camp period was a knee sprain, followed by hamstring strains and contusions. Muscle strains are the most common injury type in practices. Contact type injuries are most common during pre-season games, and the number of significant injuries that occur during preseason games is high.
    The American Journal of Sports Medicine 05/2008; 36(8):1597-603. DOI:10.1177/0363546508316021 · 4.70 Impact Factor

Publication Stats

182 Citations
27.47 Total Impact Points


  • 2008–2011
    • Hospital for Special Surgery
      • Department of Orthopaedic Surgery
      New York, New York, United States
  • 2010
    • University of Texas at Dallas
      Richardson, Texas, United States
  • 2009
    • University of California, San Francisco
      • Department of Orthopaedic Surgery
      San Francisco, CA, United States