January 2011, Volume 61, Issue 1

Original Article

Arthroscopic repair of meniscal tears with inside-out technique

Kashif Abbas  ( Department of Orthopedic Surgery, The Aga Khan University Hospital, Karachi. )
Masood Umer  ( Department of Orthopedic Surgery, The Aga Khan University Hospital, Karachi. )
Hasnain Raza  ( Department of Orthopedic Surgery, The Aga Khan University Hospital, Karachi. )


Objective: To review the clinical results of arthroscopic meniscal repair and to identify factors that may affect the outcome.
Methods: A total of 15 arthroscopic meniscal repairs with inside-out in 14 patients over a 7-year period were evaluated retrospectively. The mean age was 41.2 ± 11.5 years with a range of 26-64 years. Eleven patients underwent repair for medial meniscal tear, two patients for lateral meniscus and one patient for both in the same knee. All patients were functionally evaluated by Lysholm functional knee scores over an average follow-up of 1year and 5 months (range: 0.5-7 years).
Results: The mean Lysholm score was 84 out of a maximum of 100. Functional outcome was excellent in 6 patients, good in 5, fair in 2 and poor in one patient. The patient with poor outcome was young with a chronic tear; she had concomitant ipsi-lateral radiculopathy and also had signs of reflex sympathetic dystrophy. One 64 year old patient with fair outcome developed a post-operative flexion contracture of 15 degrees. She also had moderate osteoarthritis of the medial compartment. One patient developed saphenous nerve neuralgia which was relieved spontaneously after a few months.
Conclusion: All patients with excellent results were relatively younger with an acute tear. Elderly patients with concomitant osteoarthritis of the knee joint did not have a satisfactory outcome even if the tear was acute.
Keywords: Arthroscopic repair, Meniscal tear, Inside out technique (JPMA 61:10; 2011).


Menisci are vital for the functional well being of the knee. An intact meniscus is crucial for maintaining normal knee function, such as shock absorption, joint lubrication and load transmission across the knee joint. It increases contact area and hence decreases contact stress on the articular cartilage.1,2
Fairbank in 1948 reported that, if the meniscus is totally or partially excised for meniscal tear treatment, the incidence of subsequent arthritis is significantly increased.3,4 A meniscal tear can lead to knee osteoarthritis, but knee osteoarthritis can also lead to a spontaneous meniscal tear through breakdown and weakening of meniscal structure.5 Hence, it is desirable to preserve menisci whenever possible by repairing them.6 However, all meniscal tears are not amenable to repair, and each case must be critically assessed for repair suitability.7
Warner and Harner classified meniscal tears on the basis of their location in three zones of vascularity — red-red (fully within the vascular area), red-white (at the border of the vascular area), and white (within the avascular area). They use this classification to determine the potential for healing after repair. Tears in red-red and red-white zones have good potential for healing after repair.8 Successful repair and healing relieves meniscal symptoms and allows the patient to return to full function.9
Thomas Annandale performed the first open meniscal repair in 1883 and Hiroshi Ikeuchiis credited with performing the first arthroscopic meniscal repair in 1969 in Tokyo.10 Meniscal repair techniques have evolved over time from initial open repair to arthroscopically assisted inside-out, outside-in and all inside techniques. Arthroscopically assisted inside-out suture repair technique is well established and considered the gold standard,11 but some studies showed no difference in healing between all inside and inside-out suture repair technique,9 and inside-out versus outside-in repair technique.12
This study was conducted to review our clinical results of meniscal repair by arthroscopically assisted inside-out technique and to identify factors that may affect results, which in turn influence our future management of such cases.

Patients and Methods

This is a case series, including retrospective review of all patients who underwent arthroscopic assisted meniscal repair for isolated meniscal injury. Patients who had stable tears which were not subluxating into the joint or who had concomitant procedures done such as anterior cruciate ligament reconstruction or proximal tibial fracture fixation were excluded.
All patients presented with pain and limitation of range of motion of the knee joint. They could not squat and had difficulty in walking. Data was collected and analysed on SPSS version 16.0.
Patients were divided into two groups based on the time interval between onset of symptoms and repair, early (within 3 months) and late (beyond 3 months).
All patients were treated arthroscopically with inside-out technique. This technique, as the name implies, involves placing sutures into the knee by a needle through a cannula and retrieving outside the joint capsule. A few centimeter incision was made, dissecting and retrieving the sutures just outside the capsule and tying a secure knot. Additional sutures were then placed in similar fashion at approximately 3 to 5-mm intervals to complete the repair. Vertical sutures were placed for all tears. After suturing, the stability of the stitches were checked by arthroscopy. In almost all cases size 1 prolene was used except one in which size 1 PDS suture was used as prolene was not available on one day, but PDS can also maintain its strength for at least 6 months which is good enough time for the meniscus to heal. Though this patient had a good clinical outcome but still it is recommended to use Prolene 1 as the suture of choice. Any additional procedures that promote and augment healing were not done such as trephine, drilling or fibrin clot.
Immediately after the operation, the knee was immobilized in a brace with intermittent range of motion at knee, for 4 weeks depending on the size, extent and stability of the tear. The postoperative regime was partial weight bearing for 4-6 weeks. Activity was then gradually increased over the next few weeks. Squatting and running activities were not allowed for 3 months. Sports activities were permitted only after 6 months. Healing of all repairs were assessed clinically; no imaging study was done for confirmation due to cost constraints.

A questionnaire based on the Lysholm functional knee scores was filled by the patient himself or one of the authors in the clinic during patient\'s follow up visit or by conversation with patient on telephone. Clinical assessment of results was based on questionnaire analysis. The scores of 95and above out of 100 were considered excellent, 84 to 94 good, 65 to 83 fair and below 65 were poor. The functional outcome in patients with excellent and good scores were accepatable while fair and poor outcome were unaccepatable. Lysholm functional knee scoring system is well established and has acceptable reliability, validity and responsiveness.13


A total of 15 arthroscopic meniscal repair were done with inside-out technique in 14 patients, (8 females and 6 males) over the period of seven years, from January 2001 to December 2007.
The mean age at repair was 41.2 ± 11.5 years. Only four patients were above the age of 50 years. Three had a good outcome and one a fair outcome. Increasing age was not considered a barrier for repair of the meniscus as long as it was a traumatic and non-degenerative tear which was amenable to repair.

Ten patients were below the age of 50 years. Eleven patients were treated for medial meniscal tear, two for lateral and one for both in the same knee. Right and left knees were equally affected. Six patients had early and eight had late repairs. Twelve injuries were traumatic including sports related injuries and road traffic accidents.
All tears which were located in the peripheral vascular zone i.e. outer one third and at meniscosynovial junction were repaired. There were 12 longitudinal tears, one oblique tear and two cases with bucket handle tears. All of them were greater than 1 cm, and all were located in the posterior or postero-lateral horn. All of these were unstable tears which were dislocatable but reducible into the joint. The articular cartilages in all cases were found to be preserved except one where we found early degenerative changes.
The average post-operative follow up duration was one year and 5 months (range 6-84 months). Functional outcome was excellent in 6 patients, good in 5, fair in 2 and poor in one patient.

The mean Lysholm score was 84. All eleven patients with excellent outcome were of age less than fifty years. All patients were happy and satisfied with the outcome at the time of final analysis; three patients were not fully satisfied and they had fair or poor outcome.
Unacceptable results were found in 3 patients and all these had chronic tears.
The patient with poor outcome was young with a chronic tear, she had concomitant ipsilateral radiculopathy and also had signs of reflex sympathetic dystrophy. One 64 year old female patient with fair outcome developed a post-operative flexion contracture of 15 degrees. She also had mild osteoarthritis of the medial compartment. Both patients with lateral meniscal repair had acceptable outcome.
One patient who underwent both medial and lateral meniscal repair for acute tears had an excellent outcome. One patient developed saphenous nerve neuralgia which was relieved gradually within six months without any surgical intervention.


The clinical outcome of arthroscopic meniscal repair is reported variably in different reports. Hantes et al reported 95% success rate in 20 repairs with average follow up of 22 months, whereas Satish et al reported 66% success rate with average follow up of 21 months.14,15 Acceptable clinical outcome rate in this study was found in 78% of patients with average follow up of 18 months.
The mechanism of injury of original tear, whether traumatic or atraumatic may affect the outcome. Atraumatic tears are low energy tears usually found in knees with degenerative changes. One of the two patients with atraumatic tears in our study has fair outcome which is unsatisfactory. It is believed that healing potential of atraumatic tear is poor so it is not recommended to repair it, if the history is suggestive.
It was also noted that patients with excellent results were all relatively younger patients with ages less than fifty years. Mesiha et al also reported their observation that menisci in older patients are more vulnerable to degeneration hence failure of repair is common, leading to poor functional outcome.16
The failure rate of medial meniscal repair was 21.4% compared to none for the lateral meniscus. Other reports have also indicated a relatively higher failure rate of medial over lateral meniscal repairs.17,18
At present, there is no universal agreement as to what rehabilitation protocol is best. Shelbourne promoted a more aggressive approach and some believed in allowing range of motion and ambulation as tolerated immediately after the surgery, while others followed a restrictive rehabilitation programme.11 Barber reported no significant difference in conservative and aggressive post-op regimen.19 Rehabilitation protocol in this study was based on known guidelines.17
Henning et al reported that the failure rate in isolated meniscal repairs decreased from 41 to 8% with the use of fibrin clots.20 Fibrin-clot augmentation is believed to aid meniscal healing by acting as a chemotactic and mitogenic stimulus for repair cells and providing a scaffold for repair.21,22 Any such procedure was not used in our study that promotes and augments healing.
In our study better outcome was seen in repairs which were carried out within 3 months of initial injury. It is not clear from literature whether the time period from injury to repair has some role in prognosis. No significant difference was reported by Johnson et al in healing between early and late repairs.23 However, other studies have demonstrated good success rate in early repairs.24
The incidence of complications is generally low in arthroscopic meniscal repair. The overall complication rate in our series was 14.2%. One patient with saphenous nerve neuralgia got relieved without surgical intervention. This is a known phenomenon on the medial side and usually subsides spontaneously.11,25
Some factors have been identified in this study which may influence the clinical results of meniscus repair which are worthy of further investigation. The isolated atraumatic meniscal tear in a stable knee may not be amenable to surgical repair, especially if presentation is delayed, even if the tear is \'peripheral\'. The ideal post-operative rehabilitation programme in such cases may still need further refinement.


Clinical healing and acceptable results were achieved in 78.6% patients undergoing repair for torn menisci. All patients with excellent results were relatively younger. Elderly patients with a concomitant osteoarthritis of the knee joint did have a satisfactory outcome. Early repairs within 3 months of injury give better results than late repairs.
The authors did not receive any funding or grants in support of their research.


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