Postmeniscectomy Knee Research Articles

Treatment of post-meniscectomy knee symptoms with medial meniscus replacement results in greater pain reduction and functional improvement than non-surgical care

PurposePartial meniscectomy is a common orthopedic procedure intended to improve knee pain and function in patients with irreparable meniscal tears. However, 6–25% of partial meniscectomy patients experience persistent knee pain after surgery. In this randomized controlled trial (RCT) involving subjects with knee pain following partial meniscectomy, it was hypothesized that treatment with a synthetic medial meniscus replacement (MMR) implant provides significantly greater improvements in knee pain and function compared to non-surgical care alone.MethodsIn this prospective, multicenter RCT, subjects with persistent knee pain following one or more previous partial meniscectomies were randomized to receive either MMR or non-surgical care. This analysis evaluated the 1-year outcomes of this 2-year clinical trial. Patient-reported knee pain, function, and quality of life were measured using nine separate patient-reported outcomes. The primary outcomes were the pain subscale of the Knee injury and Osteoarthritis Outcome Score (KOOS) and the average of all five KOOS subscales (KOOS Overall). Treatment cessation was defined as permanent device removal in the MMR group and any surgical procedure to the index knee in the non-surgical care group.ResultsTreated subjects had a median age of 52 years old (range 30–69 years) and one or more previous partial meniscectomies at a median of 34 months (range 5–430 months) before trial entry. Among 127 subjects treated with either MMR (n = 61) or non-surgical care (n = 66), 11 withdrew from the trial or were lost to follow-up (MMR, n = 0; non-surgical care, n = 11). The magnitude of improvement from baseline to 1 year was significantly greater in subjects who received MMR in both primary outcomes of KOOS Pain (P = 0.013) and KOOS Overall (P = 0.027). Treatment cessation was reported in 14.5% of non-surgical care subjects and only 4.9% of MMR subjects (n.s.).ConclusionTreatment with the synthetic MMR implant resulted in significantly greater improvements in knee pain, function, and quality of life at 1 year of follow-up compared to treatment with non-surgical care alone.Level of evidenceI.

Early Clinical Results of the NUsurface® Meniscus Implant vs. Non-Surgical Controls at 12 Months

Demonstrate early comparative KOOS Overall outcomes of the NUsurface® synthetic meniscus implant versus non-surgical controls in treatment of persistent post meniscectomy knee pain. 242 patients enrolled in a pooled population comparing the investigational device to non-surgical standard of care. Of the 242 patients whose follow-up exceeds 12 months, 163 patients were treated with the meniscus implant, and 49 were treated non-surgically. Validated KOOS scores at baseline, 6-weeks, 6-months, and 12-months were obtained from all patients, with “clinically significant improvement” defined as an increase of 20 KOOS points, based on Roos et al., (2003). The investigational and control cohorts were compared at each time point using a two tailed t-test. All baseline cohort comparisons of demographics and KOOS Overall were not statistically different (p>0.05). Improvement in KOOS Overall for the investigational and control cohorts at 6-months and 12-months were 19.9 and 8.8 points, and 25.7 and 12.5 points, respectively (Figure 1). These data show a statistically significant improvement, above the clinically meaningful threshold, in the investigational arm versus the control arm as early as 6 months (p<0.001), continuing through the 12-month timepoint (p<0.001). At 12 months, 5.1% (9) investigational vs. 12.1% (8) control patients were deemed study failures due either to removal of the investigational device, or non-surgical control patients receiving surgical intervention. Adverse event analysis showed that at 12 months, more patients progressed to advanced knee reconstructive procedures in the non-surgical control group (7.5% n=5) than the investigational group (1.1% n=2). Early results of effectiveness using KOOS Overall measurement are encouraging. The investigational treatment showed statistically different outcomes, above the clinically important threshold, at 6 and 12 months, compared to non-surgical controls. The clinical study is ongoing, with long-term results to be reported in the future.

T2 Mapping Values in Postmeniscectomy Knee Articular Cartilage after Running: Early Signs of Osteoarthritis?

Loading on the joints during running may have a deleterious effect on post-partial meniscectomy knee cartilage, leading to osteoarthritis. Utilizing T2-mapping measurements before and after running may enable the observation of changes in the articular cartilage of the postmeniscectomy knees compared with healthy knees. After medial partial meniscectomy, 12 volunteers underwent magnetic resonance imaging (MRI) of the both knees, before and immediately after 30 minutes of running. Quantitative assessment of articular cartilage was performed using a T2-mapping technique. In the medial compartment of the operated knees, significantly lower T2 values were found in anterior tibial plateau (pre- vs. postrun: 33.85 vs. 30.45 ms; p = 0.003) and central tibial plateau (33.33 vs. 30.63 ms; p = 0.007). Similar differences were found in lateral regions of central femur (post- vs. prerun: 35.86 vs. 40.35 ms; p = 0.015), posterior femur (34.89 vs. 37.73 ms; p = 0.001), and anterior tibia (24.66 vs. 28.70 ms, p = 0.0004). In lateral compartment, postrun values were significantly lower in operated compared with healthy knees, in central femur (34.89 vs. 37.59 ms; p = 0.043), posterior femoral (36.88 vs. 39.36 ms; p = 0.017), anterior tibia (24.66 vs. 30.20 ms; p = 0.009), and posterior tibia (28.84 vs. 33.17 ms; p = 0.006). No statistical difference was found while comparing postrun to prerun healthy knees. Lower T2 values were found in operated knees after 30 minutes of running. These changes were seen in medial and lateral compartments. We suspect that running may subject the articular cartilage to excessive loads in the post-partial meniscectomy knee, loads that in healthy knee do not cause any changes.

Clinical Results of the NUsurface® Meniscus Implant versus Non-Surgical Controls at 24 months: Data from a Pooled cohort of a randomized controlled study and single arm study

Objectives:To demonstrate comparative KOOS outcomes (Symptoms, Pain, ADL, Sports/Rec, QoL, and Overall) of a synthetic meniscus implant versus non-surgical controls in treatment of persistent post meniscectomy knee pain.Methods:242 patients enrolled in a pooled population, randomized controlled trial (RCT) and single-arm study, comparing the investigational device to non-surgical standard of care. Of the first 100 patients enrolled, whose follow-up has exceeded 24 months, 65 patients were treated with the meniscus implant, and 35 were treated non-surgically (Table 1). Validated KOOS scores at baseline, 6-week, 6-month, 12-month, and 24-month time points were obtained from all patients where a “clinically significant improvement” was considered to be an increase of 20 KOOS points, based on Roos et al., (2003). The investigational and control cohorts were compared at each time point using a two tailed t-test. All baseline cohort comparisons of demographics and KOOS scores were not statistically different (p>0.05).Results:Improvement in KOOS Pain for the investigational vs control cohorts at 6-months was 25.0 vs 10.5 points at 6-months, 31.1 vs 14.5 points at 12-months, and 29.5 vs 13.6 points at 24-months, respectively (Figure 1). Similarly, improvement in KOOS Overall for investigational vs controls was 23.3 vs 8.0 points at 6-months, 29.2 vs 11.4 points at 12-months, and 29.1 vs 13.4 points at 24-months, respectively. These data show a statistically significant improvement, above the clinically meaningful threshold, in the investigational arm versus the control arm as early as 6 months (p<0.001) and continues through the 12-month timepoint (p<0.001) and the 24-month timepoint (p<0.001).At 24 months, 5 (7.7%) investigational vs. 5 (14.3%) control patients were no longer qualified to remain in the study, and deemed study failures, due to removal of the investigational device, and due to non-surgical control patients receiving surgical intervention (Table 1). Adverse event analysis showed that at 12 months, more patients progressed to advanced knee reconstructive procedures in the non-surgical, control group (n=4, 11.4%) than in the surgical, investigational group (n=2, 3.1%).Conclusion:Early results of effectiveness using KOOS subscales and KOOS overall are encouraging. The investigational treatment showed statistically different outcomes, above the clinically important threshold, at 6, 12 and 24 months compared to non-surgical controls. The clinical study is ongoing, with long-term results to be reported in the future.Table 1.Numbers are patients available to complete the KOOS questionnaire; Numbers in parentheses are percentages of the baseline population Investigational 61 (Randomized Controlled Trial) 115 (Single Arm) Non-Surgical Controls 66 (Randomized Control Trial) Total Patients at Baseline6535100Patients at 6 weeks58 (89%)33 (94%)91 (91%)Patients at 6 months63 (97%)32 (91%)95 (95%)Patients at 12 months60 (92%)29 (83%)89 (89%)Patients at 24 months59 (91%)28 (80%)87 (87%)Figure 1.

Three-dimensional finite-element analysis of aggravating medial meniscus tears on knee osteoarthritis

BackgroundThe biomechanical change during the medial meniscus damage in the process of knee osteoarthritis has not been explored. The purpose of this study was to determine the effect of aggravating medial meniscus degenerative tear on the progress of knee osteoarthritis through the finite-element simulation method. MethodsThe three-dimensional digital model of a total-knee joint was obtained using a combination of magnetic resonance imaging and computed tomography images. Four types of medial meniscus tears were created to represent the aggravating degenerative meniscus lesions. Meniscectomy of each meniscal tear was also utilized in the simulation. The compression and shear stress of bony tissue, cartilage, and meniscus were evaluated, and meniscus extrusion of the healthy knee, postinjured knee, and postmeniscectomy knee were investigated under the posture of balanced standing. ResultsBased on the results of finite-element simulation, the peak shear principal stress, peak compression principal stress, and meniscus extrusion increased gradually as the meniscus tears’ region enlarged progressively (from 7.333 MPa to 15.14 MPa on medial femur and from 6 MPa to 20.94 MPa on medial tibia). The higher stress and larger meniscus extrusion displacement in all tests were observed in the flap and complex tears. The oblique tears also had a biomechanical variation of stress and meniscus extrusion in the knee joint, but their level was milder. Both the peak value of the stress and meniscus displacement increased after the meniscectomy. ConclusionIn contrast to the damaged hemijoint, the stress applied on the healthy lateral hemijoint increased. The change of biomechanics was more obvious with the aggravation of meniscus injury. The advanced degenerative damage resulted in increasing stress that was more likely to cause symptomatic clinical manifestation in the knee joint and accelerate the progress of osteoarthritis. Moreover, we found that the meniscus injury caused higher stress concentration on the contralateral side of the joint. We also discovered that the meniscectomy can lead to more serious biomechanical changes, and although this technique can relieve pain over a period of time, it increased the risk of osteoarthritis (OA) occurrence. The translational potential of this articleIt is clear that the meniscal lesions can cause osteoarthritic knee, but the biomechanical change during the meniscus damage period has not been explored. We have evaluated the variation of stress during the aggravating medial degenerative meniscus tears and the relationship in the process of knee OA through finite-element simulation. This study does favour to obtain a better understanding on the symptoms and pathological changes of OA. It also may provide some potential directions for the prophylaxis and treatment of OA.

Likelihood of Return to Duty Is Low After Meniscal Allograft Transplantation in an Active-duty Military Population.

Meniscal allograft transplantation (MAT) is considered a viable surgical treatment option in the symptomatic, postmeniscectomy knee and as a concomitant procedure with ACL revision and articular cartilage repair. Although promising outcomes have recently been reported in active and athletic populations, MAT has not been well-studied in the high-demand military population. (1) What proportion of active-duty military patients who underwent MAT returned to full, unrestricted duty? (2) What demographic and surgical variables, if any, correlated with return to full, unrestricted duty? Between 2005 and 2015, three fellowship-trained sports surgeons (TMD, SJS, BDO) performed 110 MAT procedures in active-duty military patients, of which 95% (104 patients) were available for follow-up at a minimum 2 years (mean 2.8 ± SD 1.1 year). During the study period, indications for MAT generally included unicompartmental pain and swelling in a postmeniscectomized knee and as a concomitant procedure when a meniscal-deficient compartment was associated with either an ACL revision reconstruction or cartilage repair. Demographic and surgical variables were collected and analyzed. The primary endpoints were the decision for permanent profile activity restrictions and military duty termination by a medical board. The term "medical board" implies termination of military service because of medical reasons. We elected to set statistical significance at p < 0.001 to reduce the potential for spurious statistical findings in the setting of a relatively small sample size. Forty-six percent (48 of 104) of eligible patients had permanent profile activity restrictions and 50% (52 of 104) eventually had their military duty terminated by a military board. Only 20% (21 of 104) had neither permanent profile activity restrictions nor medical-board termination and were subsequently able to return to full duty, and only 13% (13 of 104) continued unrestricted military service beyond 2 years after surgery. Age, gender, tobacco use, and BMI did not correlate with return to full duty. Combat arms soldiers were less likely to have permanent profile activity restrictions (odds ratio 4.76 [95% confidence interval 1.93 to 11.8]; p = 0.001) and were more likely to return to full duty than soldiers in support roles (OR 0.24 [95% CI 0.09 to 0.65]; p = 0.005), although these findings did not reach statistical significance. Officers were more likely to return to full duty than enlisted soldiers at more than 2 years after surgery (OR 17.44 [95% CI 4.56 to 66.65]; p < 0.001). No surgical variables correlated with return-to-duty endpoints. Surgeons should be aware of the low likelihood of return to military duty at more than 2 years after MAT and counsel patients accordingly. Based on this study, MAT does not appear to be compatible with continued unrestricted military duty for most patients. IV, therapeutic study.

Treatment options for the symptomatic post-meniscectomy knee.

To provide a current review on the evidence for management of the symptomatic meniscus-deficient knee. A literature review was performed detailing the natural history and origin of symptoms in a meniscus-deficient knee, in addition to strategies for non-surgical management, meniscus scaffolds, meniscus allograft transplantation (MAT), isolated cartilage repair, unloading osteotomies, meniscus prosthesis, and joint replacements which were revealed as treatment possibilities. Meniscus deficiency was recognized to lead to an early onset knee osteoarthritis (OA). A subset of patients develop post-meniscectomy syndrome: dull and nagging pain after a short pain-free interval subsequently to meniscectomy, which can be accompanied by transient effusions. Evidence for non-surgical management of post-meniscectomy knee pain is lacking. Two available meniscus scaffolds, indicated for symptomatic segmental meniscus deficiency, show pain relief at mid-term follow-up, and effect on joint preservation is unclear. MAT represents a durable solution for sub/total meniscus deficiency (80% survival at 10years), but it is still considered a temporary solution for post-meniscectomy pain. MAT may also reduce the progression of OA. Isolated cartilage repair without a meniscus reconstruction is commonly performed, but better results were reported with preserved or reconstructed menisci. Osteotomies are used in the combination of misaligned knee and meniscus reconstruction or as pain solution for irreversible unilateral knee structural changes following a meniscectomy. Polycarbonate-urethane medial meniscus prosthesis is currently undergoing clinical trial. Joint replacements should be limited to later stages of post-meniscectomy OA. Post-meniscectomy pain syndrome and post-meniscectomy knee OA are common findings after meniscus resection. Short-term pain relief is provided by non-surgical management, mid-term pain relief by meniscus scaffolds, and long-term relief by MAT, though each has differing indications. In later stages, osteotomies and joint replacements are indicated. IV.

Meniscus Repair and Replacement

The importance of preserving the function of the meniscus is seen with renewed interest. There has been an evolution of arthroscopic meniscus repair from inside-out, outside-in, meniscal fixators, to all-inside suturing techniques. Tear patterns once ignored or thought to be irreparable, such as root tears and horizontal cleavage tears, have recently been undergoing repair with promising results. Newer techniques have also recently allowed surgeons to address postmeniscectomy knee pain. Replacing lost tissue with scaffolds or replacing the meniscus with an allograft helps restore function and reduce degenerative changes.

Can a Meniscus Really Regenerate So Easily? A Level-I Study Says It Can But Not for Everyone

Treatment options for meniscus pathology, or more specifically meniscal deficiency, are limited, with the primary focus being on meniscal preservation. Ever since 1948, when Fairbank1 introduced the concept of the post-meniscectomy knee, we have struggled to develop an improved treatment strategy for knees following a partial or complete meniscectomy. As the rate of meniscal injuries continues to rise, a high-level study on meniscal regeneration is timely. This randomized, double-blind, prospective study is one of few Level-I studies that has investigated treatments for meniscal deficiency and, to my knowledge, the only one to date to study meniscal regeneration following the injection of allogeneic mesenchymal stem cells into the knee following a subtotal meniscectomy. The authors’ objectives were to (1) study the safety of intra-articular injection of allogeneic mesenchymal stem cells into the knee joint, (2) determine the ability of mesenchymal stem cells to promote meniscus regeneration following a subtotal meniscectomy, and (3) report the effects on osteoarthritis in the knee joint following an injection of mesenchymal stem cells after a subtotal meniscectomy. Sixty adult patients from seven institutions were manually randomized to receive one of three different injections into the knee seven to ten days following a subtotal meniscectomy. The treatments were as follows: an injection of a low concentration of mesenchymal stem cells (50 million cells) suspended in hyaluronic acid, an injection of a high concentration of mesenchymal stem cells (150 million cells) suspended in hyaluronic acid, or a vehicle control of hyaluronic acid alone. Follow-up at the intervals of six weeks, six months, one year, and two years included clinical and safety evaluations, magnetic resonance imaging (MRI), and assessments of Lysholm knee scale scores and pain scores based on a visual analog scale (VAS). With respect to safety, there was no difference in minor or serious adverse events, …

Pre-operative self-efficacy and pain catastrophizing are associated with knee biomechanics during gait post-meniscectomy

s / Osteoarthritis and Cartilage 21 (2013) S63–S312 S99 in IE rotation (r21⁄40.33) and total reaction moments (r21⁄40.66). There were no differences in walking speed or step-length for any treatment. Conclusion: The shift towards greater tibia internal rotation and the association with external joint moments suggests that with treatment of Celecoxib there may be a lessening of bracing or co-contraction around the joint that results from pain and inflammation. A rotational shift in joint kinematics has previously been linked with patterns of cartilage thinning. The different kinematic response between the two treatment arms suggest potential differences in the impact of these drugs on ambulation and may have implications for different rates of disease progression that require further study. 171 PRE-OPERATIVE SELF-EFFICACY AND PAIN CATASTROPHIZING ARE ASSOCIATED WITH KNEE BIOMECHANICS DURING GAIT POSTMENISCECTOMY C.-J. Hsieh, S.Z. George, J.A. Dominguez, M.W. Moser, T.L. Chmielewski. Univ. of Florida, Gainesville, FL, USA Purpose: Meniscectomy is a risk factor for developing knee osteoarthritis (OA) and potentially leads to altered gait. Altered gait (e.g. reduced knee angle excursion and knee extensor moment and lower peak vertical ground reaction force) can change articular cartilage loading and contribute to the onset of OA. A variety of impairments could lead to altered gait, including abnormal psychosocial factors. Few studies have investigated the effect of psychosocial factors on gait, particularly in people with meniscectomy. From a clinical perspective, such research could help identify rehabilitation targets for the recovery of normal gait to possibly minimize the risk of knee OA. Therefore, the purpose of this study was to 1) examine gait biomechanics after meniscectomy, and 2) determine if pre-operative psychosocial factors are associated with post-meniscectomy knee biomechanics during gait. Methods: Fifteen subjects with traumatic meniscal tear and meniscectomy were recruited (14 males; mean age: 20.1 2.9yrs; 10 lateral/5 medial meniscectomy). Questionnaires for psychosocial constructs were administered pre-operatively and included pain catastrophizing [Pain Catastrophizing Scale, PCS; range1⁄40-52 points], fear of movement/re-injury [Tampa Scale for Kinesiophobia, TSK-11; range1⁄411-44 points], and self-efficacy for knee activity [Knee Activity Self-Efficacy Scale, KASES; range1⁄40-100 points]. Higher scores indicate higher levels of the given construct. Gait analysis was conducted after rehabilitation was complete (mean 1⁄4 7.5 weeks post-operative). Retro-reflective markers were placed prior to five walking trials at a self-selected speed. Marker position was recorded with a motion capture system (Motion Analysis Corp), and ground reaction forces were recorded with two force platforms (Advanced Mechanical Technology Inc). Sagittal plane knee angle excursion, knee extensor moment and peak vertical ground reaction force (PVGRF) were analyzed bilaterally during weight acceptance. Gait biomechanical variables were compared between sides with paired t-tests. Pearson's Product Moment correlation determined the association between pre-operative questionnaire scores and postoperative gait biomechanical variables on the surgical side. Results: Compared to the non-surgical side, the surgical side showed reduced sagittal plane knee angle excursion and knee extensor moment during weight acceptance (p1⁄4.001 and p1⁄4.002, respectively, Table). Gait biomechanical variables and questionnaire scores Variable Surgical side Non-surgical side Points Knee angle excursion ( ) 13.05 (4.51) 16.48(4.37) Knee extensor moment (N-m/kg) 0.07(0.17) 0.18(0.18) Peak vertical ground reaction force (N) 996.51(316.28) 1005.53(283.43) Pain Catastrophizing Scale (PCS) 10.93(8.32)

Meniscal scaffolds: Early experience and review of the literature

IntroductionMeniscal scaffold implants support the in-growth of new "meniscus like" tissue with the aim of alleviating post-meniscectomy knee pain and preventing further articular cartilage degeneration. Patients and methodsTwenty-three patients underwent meniscal scaffold implantation (14 medial, 9 lateral) with either the Menaflex (ReGen Biologics) (n=12) or Actifit (Orteq) (n=11) scaffolds. Minimum follow-up was 1year with a mean of 24.1months (18–27) for the Menaflex and 14.7months (12–18) for the Actifit groups. Mean age at surgery was 35years (17–47) with a mean Outerbridge grade of 1.9 in the affected compartment. Eight (36%) underwent concurrent osteotomy, ligament reconstruction or microfracture of the tibial plateau. KOOS, Lysholm, Tegner activity and IKDC scores were collected pre-operatively and at six-month interval post-surgery. Assessment of the reconstruction was obtained with MRI scanning and arthroscopy. One scaffold tore and was revised at 19months post-operatively. ResultsTwenty-one out of 23 (91.3%) had a significant improvement in knee scores when compared to pre-surgery levels at latest follow-up. Second-look arthroscopy in 14 at 1-year post-implantation showed variable amounts of regenerative tissue. There was no progression in chondral wear noted on repeat MRI scanning. ConclusionTreatment with meniscal scaffold implants can provide good pain relief for the post-meniscectomy knee following partial meniscectomy. Longer follow-up is required to ascertain whether they also prevent the progressive chondral wear associated with a post-meniscectomy knee.

Prospective Evaluation of Concurrent Meniscus Transplantation and Articular Cartilage Repair

Background Recognition of the symbiotic relationship between the meniscus and articular cartilage is critical to the success of meniscal allograft transplantation. Simultaneous combined meniscal allograft transplantation and cartilage restoration procedures have been proposed for patients with a symptomatic postmeniscectomy knee with a focal chondral defect that would have traditionally been considered a contraindication to meniscal allograft transplantation. Hypothesis Combined meniscal allograft transplantation and cartilage restoration procedures can be used to neutralize traditional contraindications to meniscal allograft transplantation with results comparable to either procedure performed in isolation. Study Design Case series; Level of evidence, 4. Methods Thirty patients underwent 31 combined meniscal allograft transplantation and cartilage restoration procedures between 1997 and 2004. These patients were prospectively studied, and completed standardized outcome surveys (including Lysholm, International Knee Documentation Committee, and Short Form-12 scales) preoperatively and annually thereafter for a minimum of 2-year follow-up. Patients were grouped according to concomitant procedure: 16 (52%) underwent meniscal allograft transplantation combined with autologous chondrocyte implantation; 15 (48%) had meniscal allograft transplantation combined with an osteochondral allograft. Two patients were lost to follow-up, leaving 29 procedures for review. Results As a combined group, statistically significant improvements were observed in all standardized outcomes scores and satisfaction scales, except Short Form-12 mental, at a mean 3.1-year follow-up. Excluding the 2 lost to follow-up, 76% of all study participants (80% autologous chondrocyte implantation; 71 % osteochondral allograft) reported that they were completely (31 %) or mostly (45%) satisfied with their results. Overall, 48% of patients (60% autologous chondrocyte implantation; 36% osteochondral allograft) were classified as normal or nearly normal at their most recent follow-up using the International Knee Documentation Committee examination score. Ninety percent of patients would have the surgery again. Conclusion Combined meniscal allograft transplantation and cartilage restoration offers a safe alternative for patients with persistent symptoms after meniscectomy and focal cartilage injury. Results of combined procedures were comparable to published reports of these procedures performed in isolation. Long-term follow-up is needed to define the survivorship of these procedures in a young patient population.

Gait analysis of pre- and post-meniscectomy knee: A prospective study

Degenerative changes in the knee joint after meniscectomy are well known. Although likely to be due to changed biomechanics, there is no evidence in the literature to identify the underlying biomechanical alterations. The aim of this study was to analyse lower limb gait biomechanics before and after meniscectomy. Ten patients who required partial medial meniscectomy for irreparable meniscal tear took part in motion analysis before surgery, then at 6 and 12 months post-operatively. A control group was also set up consisting of 10 healthy volunteers. Joint kinematics did not show significant alterations between pre-operative and 6 month post-operative evaluations. However flexion increases at the hip, knee and ankle joint were observed in late swing and early stance phase 12 months after surgery. Hip and knee flexion–extension moments were affected with knee moment altered both before and after surgery. Before surgery and at 6 months after, the changes occurred mainly at the point of push off, while at 12 months they occurred during the swing phase. Hip flexion–extension moment had also changed 12 months after surgery. When examining symmetry of gait patterns prior to surgery, there were differences between the flexion–extension moments of the healthy and of the injured knee at first impact and during late stance. After surgery, asymmetries were not more apparent at first impact, but in late stance phase a reduced knee extension moment in the injured limb was still present. Before surgery, the joint kinematics were not greatly altered and changes were mainly due to pain. After partial meniscectomy, the pain disappeared and new joint responses were observed. These could be caused by the altered mechanics and/or through proprioceptive mechanisms.

Unicompartmental Arthroplasty in the Post-Meniscectomy Knee: The Oxford Knee

Unicompartmental arthroplasty of the knee has become an accepted treatment alternative for limited osteoarthritis of the knee. Clinical studies are helping to determine which patients with unicompartmental arthritis of the knee have the most to gain from the limited nature of this surgery. The medium-term clinical results of properly selected patients are comparable to those of total knee arthroplasty. The small components used lend themselves to minimally invasive surgery. The Oxford unicompartmental arthroplasty has been developed to solve the problem of the kinematic conflict in knee arthroplasty design. The two separate articulating surfaces allow for simultaneous high congruency of both articulations while allowing the natural sliding motion in the sagittal plane. Strict attention to surgical technique and patient selection can help to achieve excellent arthroplasty longevity with high patient satisfaction.

Minimally Invasive Unicondylar Arthroplasty in the Post-Meniscectomy Knee: Repicci Knee

SUMMARYLoss of the meniscus decreases contact area, resulting in increased stress on the articular cartilage of the knee. Osteoarthritis frequently develops and sclerotic bone is exposed on the articular surfaces of the joint. In the medial compartment, this process is characterized by loss of artic

Natural History of the Post-Meniscectomy Knee

Understanding the natural history of the post-meniscectomy knee and having an appreciation for factors that influence surgical outcome enable the surgeon to individualize patient treatment and optimize results. This article reviews the various biomechanical changes in the knee after meniscectomy. There is a resultant increase in tibiofemoral contact forces proportional to the amount of tissue removed, and an alteration in knee kinematics. Clinical studies that characterized the results after meniscectomy in terms of patient functional outcome and radiographic changes are also reviewed. Several studies have demonstrated that results after meniscectomy are negatively influenced by pre-existing osteoarthritis, chondral damage, anterior cruciate ligament deficiency or other significant ligament injury, extent and location of meniscectomy (lateral vs. medial), type of meniscal tear (degenerative vs. traumatic), and knee malalignment. However, there is no definitive correlation between gender and age and surgical outcome after partial meniscectomy, provided that the knee has no other concomitant pathology.

Nonsurgical Options for the Post-Meniscectomy Knee

Nonsurgical Options for the Post-Meniscectomy Knee

Meniscal reconstruction: Present and future

Our treatment of meniscal pathology has changed dramatically over the last 30 years. What began with totalmeniscectomy is now ending with meniscal replacement. Basic science investigation of the preservation, healing, and function of meniscal replacement substitutes has shown that meniscal reconstruction is feasible and successful by various limited criteria. Clinical studies seem to suggest that the ideal candidate may be a young individual with early cartilage wear (grade I or II) who is ligamentously stable without articular incongruity. Surgical techniques using fresh-frozen and cryopreserved meniscal allograft have included open and arthroscopically assisted insertion techniques. Anchoring of the meniscal horns has been described using soft tissue, bone plugs or blocks, or a bony bridge connecting the anterior and posterior horns. Attempting to draw conclusions by comparing the results of the few preliminary studies that have been published is exceptionally difficult. Differences in patient selection, concomitant procedures, meniscal substitute selection, surgical technique, graft fixation, rehabilitation, and length of follow-up make this nearly impossible. Standardized methods for patient selection, operative technique, rehabilitation, and length of follow-up need to be determined to further define meniscal replacement techniques. It remains cautiously optimistic that meniscal replacement remains a treatment for the postmeniscectomy knee.

Arthroscopically assisted technique for meniscal reconstruction using fresh frozen allograft

Meniscal transplantation has been developed as a rationale of treatment for knees that have previously undergone a complete meniscectomy. In reconstructing the human meniscus, it is believed that the onset of the progressive degenerative changes that occur in the postmeniscectomy knee may be delayed. This will only occur if the reconstructed meniscus is able to perform all of its functions: increase of contact area, decrease of contact stress, shock absorption, joint lubrication, nutrition of chondrocytes, and stabilization. An arthroscopically assisted technique for meniscal reconstruction using fresh frozen meniscal allograft with attached bone plugs is described. This technique, which avoids disruption of the extensor mechanism or collateral ligaments, emphasizes arthroscopic visualization of specific anatomic landmarks for each meniscal root insertion site, with creation of osseous tunnels at these corresponding sites to allow for anatomic placement of the meniscal implant. Although early clinical results seem promising, this procedure should be limited to a select group of individuals who meet specific inclusion criteria in study groups and investigational protocols until long-term results are determined.

Meniscal reconstruction using allograft tissue: An arthroscopic technique

The treatment of meniscal pathology has changed dramatically over the last decade. This change in treatment has been brought about by our increased knowledge of the functions of the human meniscus: force transmission, increase contact area, decrease contact stress, shock absorption, joint lubrication, nutrition of chondrocytes, and stabilization. Meniscal transplantation has been developed in an attempt to interrupt or retard the progressive joint deterioration that develops in the postmeniscectomy knee. The author's arthroscopically assisted technique for meniscal reconstruction using fresh frozen allograft tissue without disruption of the extensor mechanism or collateral ligaments is described. This technique emphasizes visualization of specific landmarks for each meniscal horn insertion site with creation of osseous tunnels at these corresponding sites to allow for anatomic placement of the meniscal inplant. Only if normal anatomy and kinematics is established can one assume that the transplanted meniscus will provide a beneficial function. The author's believe that the operation should be limited to a select group of individuals who meet specific inclusion criteria in study groups and investigational protocols until long-term results are determined.