Arthroscopic Primary Repair of the Anterior Cruciate Ligament (ACL)
Condition: Rupture of Anterior Cruciate Ligament
MeSH terms: Rupture
Study type: Interventional

Summary: 
      A prospective cohort study that will be conducted at Sultan Qaboos University Hospital. It
      aims to determine the outcomes, in terms of, activity level, functional level, subjective
      knee function, range of motion, stability, and failure, among patients with acute ACL
      injuries, who undergo arthroscopic primary ACL repair; and to compare these results with
      patients who undergo arthroscopic ACL reconstruction. To the investigators' knowledge, there
      is a dearth of studies looking into the outcomes of arthroscopic primary ACL repair and this
      going to be the first study in the Middle East. The investigators believe that arthroscopic
      primary ACL repair is superior to arthroscopic ACL reconstruction; and conducting this
      research project will elucidate the previously abandoned facts about acute ACL repair; and
      will eventually have a huge impact in the field of orthopedic surgery.
    

Detailed description: 
      Hypothesis Null hypothesis: no difference in outcomes between arthroscopic primary ACL repair
      and arthroscopic ACL reconstruction in patients with acute ACL tear.

      Alternative hypothesis: the arthroscopic primary ACL repair is superior to arthroscopic ACL
      reconstruction.

      Background Anterior cruciate ligament (ACL) is an important mechanical stabilizer during
      knee-joint movement; it is the primary restraint against anterior tibial translation relative
      to the femur; and it acts as secondary restraint to tibial rotation and varus/valgus
      rotation. ACL injuries are commonly seen among athletics; and the number is increasing, with
      a reported incidence of 38/100,000 per year. Although there is still some debate about the
      optimal treatment for acute ACL tears, surgical management in the young and active patient is
      recommended. The surgical management options to an isolated ACL tear vary from acute repair
      to ligament reconstruction. Acute ACL repair can be classified into: acute primary repair,
      acute repair with the use of a ligament augmentation device, and acute repair with
      augmentation with an autologous hamstring tendon graft. The outcome of acute repair of ACL
      rupture from its femoral attachment or a proximal tear close to it, is the aim to be
      accomplished at the end of this project.

      Several studies demonstrated that the results of acute repair of ACL ruptures deteriorate
      with time and the procedure was shown to be ineffective. However, most of the published
      studies are retrospective and nonrandomized, and they compare different surgical techniques,
      rehabilitation, and follow-up protocols. The surgeries were open and lengthy, the repairs
      were done on all injury types, on wide variety of ages, with varied concomitant injuries, and
      the rehab was primeval. Furthermore, there is no study that has described the long-term
      results of acute ACL repair.

      Although the concept of ACL potential healing has been deserted in the past, there is renewed
      interest in the primary healing capacity of this ligament. One would argue why there is a
      need for the repair of a torn ACL. First, the operation is simple and takes less time and
      less risk in comparison to ACL reconstruction. Second, ACL treatment aims to provide
      immediate knee stability; resolve the pain and avoiding long-term complications, primarily
      osteoarthritis. ACL reconstruction using an autologous or allogenic tendon graft, is
      universally accepted as the gold standard treatment for complete ACL tears, as it yields
      excellent results for instability and pain in most the patients. However, there is a higher
      failure rate in adolescents than in other age groups with up to 20% to 25% of patients
      experiencing problems postoperatively. This mandates to find a better solution for this group
      of patients. In addition, patients post ACL reconstructions were found to have higher rates
      of osteoarthritis, despite the treatment; these findings are based on long-term follow up
      studies. This emphasizes on the need to find an alternative surgical management option to
      improve the ultimate outcomes. Third, the incidence of ACL injuries in skeletally immature
      patients are increasing; and so far, there are no standardized treatment options. For this
      group of patients, the transphyseal ACL reconstruction with grafts carries a risk for limb
      length and angular deformities, although several studies have proven no increase in the rate
      of such complications. Hence, the pre-pubescent population has the potential to benefit
      greatly from this regenerative treatment, which does not violate the physes; and they respond
      remarkably to certain biological stimuli implemented in the current enhanced repair
      techniques. Fourth, regeneration of the ACL over reconstruction preserves the remaining
      proprioceptive fibers within the ligament substance, and maintains the complex insertion
      sites of the ligament. This could potentially lead to more normal biomechanics of the knee if
      adequate regeneration is achieved.

      Material and methods This is a prospective cohort study that will be conducted at Sultan
      Qaboos University Hospital (SQUH) and it involves patients with acute ACL injury attending
      the orthopedic clinic. The ACL rupture will be assessed clinically by anterior drawer test
      (ADT), Lachman's test, and pivot shift test. The ACL tear will be confirmed by knee MRI.

      The ethical approval and permission from the concerned institution is required to start the
      study. All eligible patients who consent to participate will be included in the study.

      The arthroscopic ACL repair will be carried out by one expert orthopedic surgeon. Because
      arthroscopy is a reference standard for the diagnosis of internal derangements of the knee,
      and because it is unethical to sacrifice a torn ACL that can be repaired; the patients will
      be assessed intra-operatively, and will be divided into two groups (group 1= ACL repair);
      group 2= ACL reconstruction) based on ACL amenability for repair or reconstruction. If the
      ACL was found to have a good tissue quality and fulfilling the inclusion criteria, it will be
      repaired using fiberwires and anchored to the femoral condyle using SwiveLock screw. If the
      ACL found irreparable, then it will be reconstructed using hamsting tendons graft. A minimum
      of 20 patients will be included in each group.

      Post-operatively, the patients will undergo a specific rehabilitation program and will be
      followed up for, at least, one year to determine their activity level, functional level,
      subjective knee function, range of motion, stability, and failure of the repair.

      The activity level will be evaluated using Tegner activity score, which is a scale that aims
      to provide a standardized method of grading work and sporting activities. It describes the
      current level of activity and that before injury. The score varies from 0-10; a score of 0
      represents sick leave or disability pension because of knee problems, whereas a score of 10
      corresponds to participation in national and international elite competitive sports.

      The functional state will be graded using Lysholm scale, which is designed to assess how the
      knee problems have affected the patient's ability to manage in everyday life. It consists of
      8 items that assess: pain (25 points), instability (25 points), locking (15 points), swelling
      (10 points), limp (5 points), stair climbing (10 points), squatting (5 points), and need for
      support (5 points). Every question response has been assigned an arbitrary score on an
      increasing scale. The total score is the sum of each response to the eight questions, and may
      range from 0-100. The scores are categorized as: Poor (<65); Fair (65-83); Good (84-90); and
      Excellent (>90).

      Both scales will be translated into Arabic; then back-translation will be done into English,
      all by experts, to ensure absolute quality and accuracy.

      The subjective knee function will be graded as poor, fair, good, and excellent.

      The knee stability/anterior laxity will be assessed using ADT, Lachman's test, and pivot
      shift test. The ADT is graded as:

        -  Negative (0)

        -  +1: <5 mm translation,

        -  +2: 5 to 10 mm,

        -  +3: >10 mm translation.

      The Lachman's test is graded as:

        -  Negative (0),

        -  Slight (1+): <5 mm of displacement,

        -  Moderate (2+): 5 to 10 mm,

        -  Severe (3+): >10 mm compared with that of the normal knee.

      The pivot shift is graded as:

        -  Negative (0)

        -  Trace positive (1+),

        -  Moderate shift (2+),

        -  Subluxation (3+).

      The patients will be evaluated by an independent observer.

      The participants' data, including the personal information, will be kept safe and secure. The
      date will be anonymised with ID numbers. The hard copies will be in a locked filing cabinet
      and the soft copies will be securely password protected. The data will only be accessed by
      the agreed members of the research team. These records are not to be transferred to or shared
      with any other institute.

      The Statistical Package for the Social Sciences (SPSS) will be used for the statistical
      analyses. Data collection and entry will be done by trained personnel. To assess relationship
      between variables: as univariate analysis, we will use Chi-square, t-test, ANOVA or
      non-parametric tests according to the nature of data. The nonparametric analysis of variance
      (Kruskal-Wallis test) will be used to determine the significance of the overall difference in
      the outcome measures among the two groups at a particular follow-up time-point. Paired
      comparisons among the two groups at each time-point will be made with use of the Mann-Whitney
      test. The Wilcoxon test for paired data will also be used to test for the significance of the
      changes in the outcome measures for a particular group between any two time points. Also, odd
      ratio will be calculated, where applicable. As adjusted multivariate analysis, we will use
      logistic regression. Relations between variables will be assessed by correlation coefficient.

      Feasibility of the project This study is going to be a pilot study. Its primary mission is to
      provide immediate knee stability, resolve the pain and avoid long-term complications via
      simple and straightforward arthroscopic ACL repair. It is an evolving procedure and its
      results are promising. ACL injuries are common and the procedures are being done by one
      experienced orthopedic surgeon. The assessment scales that will be used are validated and
      have been used internationally in previous studies yielding valid information. To the
      investigator's knowledge, there is a dearth of studies looking into the outcomes of
      arthroscopic primary ACL repair and this is going to be the first study in the Middle East.
      Therefore, conducting this research project will yield reliable and helpful results; will
      elucidate the previously abandoned facts about acute ACL repair; and will eventually have a
      huge impact in the field of orthopedic surgery.
    

Intervention name(s): Arthroscopic ACL Primary Repair; Arthroscopic ACL Reconstruction
Intervention type(s): Procedure; Procedure
Intervention description(s): All patients (in both groups) will undergo diagnostic knee arthroscopy at the start of the procedure; those in the experimental arm "repairable ACL tear", whose ACL found to be avulsed from its femoral insertion or has a proximal tear, and intra-operatively, found to have a good tissue quality, will undergo arthroscopic ACL primary repair using fiberwires and SwiveLock screw to anchor the ligament into its origin, in the femoral condyle.; Patients whose ACL cannot be repaired, will undergo arthroscopic ACL reconstruction using hamstring tendons.
Other intervention name(s): Diagnostic knee arthroscopy; Diagnostic knee arthroscopy
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment