Skip to Content

Jason L. Koh, M.D.

Jason L. Koh, M.D.

Jason L. Koh, M.D.

Shoulder & Knee Injuries, Hip Arthroscopy, Sports Medicine
  • Locations
    Locations
    A

    NorthShore Medical Group

    9650 Gross Point Rd.
    Suite 2900
    Skokie, IL 60076
    847.866.7846 224.251.2905 fax
    View Map: Google
    This location is wheelchair accessible.
    B

    NorthShore Medical Group

    2180 Pfingsten Rd.
    Suite 3100
    Glenview, IL 60026
    847.866.7846 866.954.5787 fax
    View Map: Google
    This location is wheelchair accessible.
  • Publications
    Publications
    • A modified Delphi consensus statement on patellar instability: part I.

      The bone & joint journal 2023 Dec 01

      Authors: Hurley ET
      Abstract
      The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach.
      A total of 60 surgeons from 11 countries were invited to develop consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest within patellar instability. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered to be unanimous.
      Of 27 questions and statements on patellar instability, three achieved unanimous consensus, 14 achieved strong consensus, five achieved consensus, and five did not achieve consensus.
      The statements that reached unanimous consensus were that an assessment of physeal status is critical for paediatric patients with patellar instability. There was also unanimous consensus on early mobilization and resistance training following nonoperative management once there is no apprehension. The statements that did not achieve consensus were on the importance of immobilization of the knee, the use of orthobiologics in nonoperative management, the indications for MPFC repair, and whether a vastus medialis oblique advancement should be performed.
      PMID: 38037678 [PubMed - as supplied by publisher]
    • A modified Delphi consensus statement on patellar instability: part II.

      The bone & joint journal 2023 Dec 01

      Authors: Hurley ET
      Abstract
      The aim of this study was to establish consensus statements on medial patellofemoral ligament (MPFL) reconstruction, anteromedialization tibial tubercle osteotomy, trochleoplasty, and rehabilitation and return to sporting activity in patients with patellar instability, using the modified Delphi process.
      This was the second part of a study dealing with these aspects of management in these patients. As in part I, a total of 60 surgeons from 11 countries contributed to the development of consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered unanimous.
      Of 41 questions and statements on patellar instability, none achieved unanimous consensus, 19 achieved strong consensus, 15 achieved consensus, and seven did not achieve consensus.
      Most statements reached some degree of consensus, without any achieving unanimous consensus. There was no consensus on the use of anchors in MPFL reconstruction, and the order of fixation of the graft (patella first versus femur first). There was also no consensus on the indications for trochleoplasty or its effect on the viability of the cartilage after elevation of the osteochondral flap. There was also no consensus on postoperative immobilization or weightbearing, or whether paediatric patients should avoid an early return to sport.
      PMID: 38035602 [PubMed - as supplied by publisher]
    • Investigating the effect of autograft diameter for quadriceps and patellar tendons use in anterior cruciate ligament reconstruction: a biomechanical analysis using a simulated Lachman test.

      Frontiers in surgery 2023

      Authors: Amirouche F
      Abstract
      Current clinical practice suggests using patellar and quadriceps tendon autografts with a 10 mm diameter for ACL reconstruction. This can be problematic for patients with smaller body frames. Our study objective was to determine the minimum diameter required for these grafts. We hypothesize that given the strength and stiffness of these respective tissues, they can withstand a significant decrease in diameter before demonstrating mechanical strength unviable for recreating the knee's stability.
      We created a finite element model of the human knee with boundary conditions characteristic of the Lachman test, a passive accessory movement test of the knee performed to identify the integrity of the anterior cruciate ligament (ACL). The Mechanical properties of the model's grafts were directly obtained from cadaveric testing and the literature. Our model estimated the forces required to displace the tibia from the femur with varying graft diameters.
      The 7 mm diameter patellar and quadriceps tendon grafts could withstand 55-60 N of force before induced tibial displacement. However, grafts of 5.34- and 3.76-mm diameters could only withstand upwards of 47 N and 40 N, respectively. Additionally, at a graft diameter of 3.76 mm, the patellar tendon experienced 234% greater stiffness than the quadriceps tendon, with similar excesses of stiffness demonstrated for the 5.34- and 7-mm diameter grafts.
      The patellar tendon provided a stronger graft for knee reconstruction at all diameter sizes. Additionally, it experienced higher maximum stress, meaning it dissociates force better across the graft than the quadriceps tendon. Significantly lower amounts of force were required to displace the tibia for the patellar and quadriceps tendon grafts at 3.76- and 5.34-mm graft diameters. Based on this point, we conclude that grafts below the 7 mm diameter have a higher chance of failure regardless of graft selection.
      PMID: 37886636 [PubMed - as supplied by publisher]
    • Liposomal Bupivacaine Interscalene Blocks Demonstrate a Greater Proportion of Total Shoulder Arthroplasty Patients with Clinically Tolerable Pain - a Retrospective Quality Improvement Study of 491 Patients.

      Journal of ISAKOS : joint disorders & orthopaedic sports medicine 2023 Oct 20

      Authors: Lee JK, Greenberg S, Wixson R, Heshmat C, Locke A, Daniel T, Koh J
      Abstract
      To evaluate the effects of liposomal bupivacaine use for interscalene blocks on postoperative analgesia in total shoulder arthroplasty patients.
      De-identified total or reverse total shoulder arthroplasty patients between 2018 and 2021 were analyzed. Patients were grouped into single shot interscalene block with Liposomal Bupivacaine (LB) with plain bupivacaine, Other Block (OB) with other local anesthetics (mepivacaine, ropivacaine, or plain bupivacaine), or No Block (NB). The primary outcome was the proportion of patients with clinically tolerable pain scores (mean VAS <4) from 0 - 24 hours in each group. Secondary outcomes included averaged visual analog pain scores (VAS) and opioid consumption measured in morphine milligram equivalents (MMEs) from 0 - 24 hours. We also analyzed the proportion of patients with clinically tolerable pain, mean VAS, and opioid consumption from 0 - 72 hours in those patients with at least a 3-day hospital length of stay.
      A total of 491 de-identified total shoulder arthroplasty patients, 285 liposomal bupivacaine group (LB), 178 other block group (OB), and 28 no block group (NB), were analyzed. The primary outcome showed a statistically significant different proportion of patients with clinically tolerable pain from 0 - 24 hours in the LB group (69%) vs. OB group (39%) vs. NB group (11%) (<0.001). Secondary outcomes included statistically significant differences in VAS (LB median = 3.35, OB median = 4.38, NB median = 5.25 (p <0.001, <0.001)) and total MME opioid consumption (LB median= 40, OB median=60, NB median=88 (p < 0.001, 0.001)) between groups from 0 - 24 hours. For patients who had hospital stays of at least 3 days, a significant association was found with having achieved clinically tolerable pain 0-72 hours and the LB group (51%) vs. OB group (21%) vs. NB group (11%) (P= 0.006). However, there was no statistical difference in mean VAS or opioid consumption between these groups.
      A greater proportion of total shoulder arthroplasty patients that received liposomal bupivacaine in interscalene block have clinically tolerable pain scores from 0 to 24 hours, lower VAS, and lower MME consumption in patients following total shoulder arthroplasty.
      Level III - Clinical Study.
      PMID: 37866512 [PubMed - as supplied by publisher]
    • A Transplant or a Patch? A Review of the Biologic Integration of Meniscus Allograft Transplantation.

      JBJS reviews 2023 Sep 01

      Authors: Lichtig A
      Abstract
      » After transplantation revascularization does occur although data are only available for animal models.» The time zero biomechanics, that is, the biomechanical properties at the time of transplant, of a meniscus allograft transplantation appear to appropriately mimic the original so long as the graft is sized correctly within 10% of the original and bone plug fixation is used.» Allograft type, that is, fresh vs. frozen, does not appear to affect the integration of the allograft.
      PMID: 37678287 [PubMed - as supplied by publisher]
    • Experts Achieve Consensus on a Majority of Statements Regarding Platelet-Rich Plasma Treatments for Treatment of Musculoskeletal Pathology.

      Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association 2023 Aug 23

      Authors: Hurley ET, Sherman SL, Stokes DJ, Rodeo SA, Shapiro SA, Mautner K, Buford DA, Dragoo JL, Mandelbaum BR, Zaslav KR, Cole BJ, Frank RM, Members of the Biologics Association
      Abstract
      To establish consensus statements on platelet-rich plasma (PRP) for the treatment of musculoskeletal pathologies.
      A consensus process on the treatment of PRP using a modified Delphi technique was conducted. Thirty-five orthopaedic surgeons and sports medicine physicians participated in these consensus statements on PRP. The participants were composed of representatives of the Biologic Association, representing 9 international orthopaedic and musculoskeletal professional societies invited due to their active interest in the study of orthobiologics. Consensus was defined as achieving 80% to 89% agreement, strong consensus was defined as 90% to 99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement.
      There was consensus on 62% of statements about PRP.
      (1) PRP should be classified based on platelet count, leukocyte count, red blood count, activation method, and pure-plasma versus fibrin matrix; (2) PRP characteristics for reporting in research studies are platelet count, leukocyte count, neutrophil count, red blood cell count, total volume, the volume of injection, delivery method, and the number of injections; (3) the prognostic factors for those undergoing PRP injections are age, body mass index, severity/grade of pathology, chronicity of pathology, prior injections and response, primary diagnosis (primary vs postsurgery vs post-trauma vs psoriatic), comorbidities, and smoking; (4) regarding age and body mass index, there is no minimum or maximum, but clinical judgment should be used at extremes of either; (5) the ideal dose of PRP is undetermined; and (6) the minimal volume required is unclear and may depend on the pathology.
      Level V, expert opinion.
      PMID: 37625660 [PubMed - as supplied by publisher]
    • Introducing the Patient-Reported Outcome Measures Workgroup and How It Is Helping Patients and Physicians Harness the Benefits.

      The Journal of the American Academy of Orthopaedic Surgeons 2023 Oct 15

      Authors: Shapiro LM
      PMID: 37580049 [PubMed - as supplied by publisher]
    • Analysis of abduction moment arms after rotator cuff tear and acellular dermal matrix allograft reconstruction.

      Journal of shoulder and elbow surgery 2023 Nov

      Authors: Krishnan P, Koh J, Pradhan S, Bobko A, Athiviraham A, Amirouche F
      Abstract
      Biomechanical testing of abduction moment arms presents a useful method to assess the contributions of individual rotator cuff muscles to glenohumeral function. This study aimed to investigate the changes in abduction moment arms after the treatment of supraspinatus tears with superior capsular reconstruction (SCR), bursal acromial reconstruction (BAR), and a combined SCR-BAR procedure, all with human dermal allograft.
      We tested 7 fresh-frozen cadaveric specimens under 6 conditions: (1) intact, (2) 50% supraspinatus tear (partial tear), (3) 100% supraspinatus tear, (4) SCR, (5) SCR combined with BAR, and (6) BAR. In each condition, the moment arms for the individual muscles of the teres minor, subscapularis, and infraspinatus were calculated throughout 90° of abduction using a motion capture system. Analysis of variance and post hoc Tukey testing were performed to determine significance.
      In the teres minor, the moment arms in the SCR (11.9 mm), BAR (10.1 mm), and SCR-BAR (11.9 mm) conditions were greater than those in the intact (8.5 mm; P = .001, P = .001, and P = .001, respectively), partial tear (9.1 mm; P = .001, P = .128, and P = .001, respectively), and complete tear (8.8 mm; P = .001, P = .011, and P = .001, respectively) conditions. Similarly, in the subscapularis, the moment arms in the SCR (13.4 mm), BAR (13.8 mm), and SCR-BAR (13.5 mm) conditions were greater than those in the intact (10.6 mm; P = .006, P = .001, and P = .003, respectively) and partial tear (10.4 mm; P = .006, P = .001, and P = .003, respectively) conditions. In the teres minor, the SCR (11.9 mm) and SCR-BAR (11.9 mm) conditions were also found to have significantly increased moment arms compared with the BAR condition (10.1 mm; P = .001 and P = .001, respectively). In the infraspinatus, the BAR condition (13.8 mm) was found to have a significantly decreased moment arm compared with the partial tear condition (15.8 mm, P = .026), with no other significant findings between conditions.
      Our results suggest that the moment arm contributions of the individual muscles comprising the rotator cuff can change after reconstruction to compensate for tears. SCR and SCR-BAR increase the moment arms in the teres minor and subscapularis, potentially allowing for increased abduction ability.
      PMID: 37276919 [PubMed - as supplied by publisher]
    • Influence of medial patellofemoral ligament reconstruction on patellar tracking and patellofemoral contact pressures in patella alta.

      Computer methods in biomechanics and biomedical engineering 2023 Jan 16

      Authors: Jones TJ, Koh JL
      Abstract
      Knee squatting was simulated to characterize the influence of medial patellofemoral ligament (MPFL) reconstruction on patellar tracking and contact pressures for knees with mild patella alta (Caton-Deschamps index = 1.3-1.4). Eight computational models represented knees in the pre-operative condition and following MPFL reconstruction. MPFL reconstruction significantly reduced patellar lateral tracking at low flexion angles based on bisect offset index, significantly decreased the maximum lateral pressure in mid-flexion, and significantly increased the maximum medial pressure in mid-flexion. MPFL reconstruction improves patellar stability for knees with mild patella alta and can reduce the pressure applied to lateral cartilage on the patella.
      PMID: 36645842 [PubMed - as supplied by publisher]
    • Clinical and Radiographic Criteria Define "Acceptable" Surgical Correction of Hip Femoroacetabular Impingement Syndrome as Well as Postoperative Complications: An International Modified Delphi Study.

      Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association 2023 May

      Authors: Defining Parameters for Surgical Correction and Outcomes for Femoroacetabular Impingement Through Consensus (DEFINE) Investigators
      Abstract
      To develop recommendations for clinical and radiographic criteria to help define the "acceptable" surgical correction of femoroacetabular impingement syndrome (FAIS) and identify/define complications postoperatively.
      A 3-phase modified Delphi study was conducted involving a case-based survey; a Likert/multiple choice-based survey concerning radiographic and physical examination characteristics to help define FAIS correction, as well as the prevalence and definition of potential postoperative complications; and 2 consensus meetings.
      Of the 75 experts invited, 54 completed the Phase I survey, 50 completed the Phase II survey (72% and 67% response rate), and 50 participated in the Phase III consensus meetings. For both typical and atypical (complex) cases, there was consensus that fluoroscopy with multiple views and dynamic hip assessment should be used intraoperatively (96% and 100%, respectively). For typical FAIS cases, the Expert Panel agreed that Dunn lateral and anteroposterior radiographs were the most important radiographs to evaluate the hip postoperatively (88%, consensus). When asked about evaluating the correction of cam impingement postoperatively, 87% voted that they use subjective evaluation of the "sphericity" of the femoral head. In the case of focal and global pincer-type FAIS, there was consensus that the reduction or elimination of the crossover sign (84%) and lateral center-edge angle (91%) were important to inform the extent of the FAIS correction. There was consensus for recommending further investigation at 6 months postoperatively if hip pain had increased/plateaued (92% agreed); that additional investigation and treatment should occur between 6 and 12 months (90% agreed); and that a reoperation may be recommended at 12 months or later following this investigation period (89% agreed).
      This consensus project identified the importance of using fluoroscopy and dynamic hip assessment intraoperatively; Dunn lateral and anteroposterior view radiographs postoperatively; evaluating the "sphericity" of the femoral head for cam-type correction and the use of dynamic hip assessment; reducing/eliminating the crossover sign for focal pincer-type FAIS; evaluating the lateral center-edge angle for global pincer-type FAIS; and avoiding overcorrection of pincer-type FAIS. In cases in which postoperative hip pain increased/plateaued, further investigation and treatment is warranted between 6 and 12 months, and a reoperation may be recommended at a minimum of 12 months depending on the cause of the hip pain.
      Hip arthroscopy surgeons have yet to reach a firm agreement on what constitutes an "acceptable" or "good" surgery radiographically and how they can achieve desired clinical outcomes. Although this was a comprehensive effort, more study is needed to determine therapeutic thresholds that can be universally applied.
      PMID: 36621448 [PubMed - as supplied by publisher]
  • In the News
    In the News

    Oct 2020

    Apr 2019

    Jul 2018

    Oct 2017

    Apr 2017

    Aug 2016

    May 2016

    Apr 2016

    Feb 2016

    Jul 2015

  • Social Media