Correlation of WOMAC and KOOS scores to tibiofemoral cartilage loss on plain radiography and 3 Tesla MRI: data from the osteoarthritis initiative

Purpose

The purpose of this study was to determine the correlation between the Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) and Knee Injury Osteoarthritis Outcomes scores (KOOS) and the degree of tibiofemoral cartilage loss on plain radiography and 3T magnetic resonance imaging (MRI). We hypothesize that these subjective outcome scores will have a significant correlation to quantitative joint space loss.

Methods

Data used in the preparation of this article were obtained from the osteoarthritis initiative (OAI) database (OAI public use data sets kMRI_QCart_Eckstein18 and kXR_QJSW_Duryea16). Four hundred and forty-five patients had WOMAC/KOOS scores, quantitative tibiofemoral joints space width on plain radiographs and quantitative tibiofemoral cartilage thickness and per cent full thickness cartilage loss on 3T MRI. Joint space width on plain radiographs was correlated to cartilage thickness on MRI, and WOMAC/KOOS scores were correlated to the degree of cartilage loss using Pearson correlation coefficients.

Results

There was a statistically significant correlation between medial and lateral compartment cartilage thickness on MRI and medial and lateral joint space width on plain radiography (r = 0.86, r = 0.80) (p < 0.001). KOOS knee pain score was significantly correlated to increasing per cent full thickness cartilage loss in the medial femoral compartment (r = 0.34) (p < 0.001). KOOS symptom score was significantly correlated to decreasing joint space width in the medial (r = 0.16) and lateral (r = 0.15) compartment and increasing per cent full thickness cartilage loss in the medial femoral compartment (r = 0.36) (p < 0.001). No WOMAC score was correlated to degree of joint space width, cartilage thickness or per cent full thickness cartilage loss (n.s).

Conclusion

The WOMAC and KOOS scores are poor indicators of tibiofemoral cartilage loss, with only the KOOS symptom and knee pain score being weakly correlated. Osteoarthritis is a multifactorial process and the need to treat patients based off their symptoms and rely on radiographs as confirmatory modalities, and not diagnostic modalities, when talking about OA and medical intervention.

Level of evidence

Level 2.     

Outcomes after ACL reconstruction with focus on older patients: results from The Swedish National Anterior Cruciate Ligament Register

Purpose

To investigate and analyse outcomes of patients over the age of 40 who had undergone anterior cruciate ligament (ACL) reconstruction and to compare them to their younger counterparts. We analysed patient-reported outcomes measured using the knee injury and osteoarthritis outcome score (KOOS) as well as aetiology of injury, concomitant intra-articular injuries and time from injury to surgery.

Methods

Data were extracted from the Swedish National Knee Ligament Register during the period of 2005 through 2012. The following data were extracted and analysed: patient age, gender, activity at the time of injury, time between injury and reconstruction, concomitant intra-articular injuries, graft size used for reconstruction and KOOS measured pre-operatively as well as 1, 2 and 5 years post-operatively. The cohort was stratified into age groups of 0–19, 20–29, 30–39 and ≥40 years of age.

Results

Pivoting sports were dominating as the cause of ACL injury in the younger age groups (up to 39 years). Alpine skiing and other non-specified activities were the most common causes in the older age group (≥40 years). Pre-operative KOOS was significantly lower in older age groups (p < 0.01). Post-operative KOOS regarding all subscales was significantly better in the older age group. The improvement in KOOS was significant with increasing age (p < 0.01). Older patients exhibited the greatest improvement in KOOS for all subscales at 1, 2 and 5 years post-operative follow-ups compared with pre-operative values (p < 0.01). Older patients had more cartilage injuries pre-operatively compared with younger patients. The same trend was observed in the older group for meniscus injury with and without cartilage injuries. The diameter of the graft used for ACL reconstruction was significantly larger in the older age groups and largest in the age group ≥40 years (p < 0.01). Older patients waited significantly longer for surgery after the ACL injury (p < 0.01).

Conclusion

In the older age groups, patients reported lower pre-operative KOOS compared with their younger counterparts. At follow-up, KOOS was similar in all age groups. From these results, we can therefore conclude that our hypothesis confirmed that optimal surgical results can in fact be achieved even in older patients.

Level of evidence

II.     

Implantation of matrix-induced autologous chondrocyte (MACI®) grafts using carbon dioxide insufflation arthroscopy

Purpose

The purpose of this study was to determine the safety of a new arthroscopic Matrix-induced autologous chondrocyte implant (MACI) technique with carbon dioxide insufflation utilized to improve visualization during the dry phase of the scaffold implant.

Methods

Between 2004 and 2007, thirty patients were treated for symptomatic focal chondral lesions of the medial femoral condyle. All patients were monitored during surgery for gas embolism signs and symptoms and were evaluated preoperatively and at a median follow-up of 70.5 months (range 48–93 months) using the KOOS subjective evaluation score, the Lysholm function score, the Tegner activity scale for the knee, and the IKDC objective score.

Results

No cases of intraoperative or postoperative symptoms or signs related to gas embolism or persistent subcutaneous emphysema were registered. Each subscale of the KOOS subjective score improved from preoperative to follow-up. The median Lysholm score was 50 (range 15–66) at baseline and 87.5 (range 54–100) at follow-up (p < 0.05). The median Tegner score was 2 (range 1–4) at baseline to 5 (range 2–7) at follow-up (p < 0.05).

Conclusions

No complications registered, and the satisfactory clinical results achieved in this series suggest that carbon dioxide insufflation during arthroscopic MACI is a safe and accessible option to improve visualization during the dry phase of the scaffold implant on medial femoral condyles.

Level of evidence

IV.     

Autologous osteochondral mosaicplasty or TruFit™ plugs for cartilage repair

Purpose

Autologous osteochondral mosaicplasty and TruFit? Bone graft substitute plugs are methods used to repair symptomatic articular cartilage defects in the adult knee. There have been no comparative studies of the two techniques.

Methods

This retrospective study assessed functional outcome of patients using the EQ-5D, Knee Injury and Osteoarthritis Outcome Score (KOOS) and Modified Cincinnati scores at follow-up of 1–5 years.

Results

There were 66 patients in the study (35 TruFit and 31 Mosaicplasty): 44 males and 22 females with a mean age of 37.3 years (SD 12.6). The mean BMI was 26.8. Thirty-six articular cartilage lesions were due to trauma, twenty-six due to osteochondritis dissecans and three due to non-specific degenerative change or unknown. There was no difference between the two groups age (n.s.), sex (n.s.), BMI (n.s.), defect location (n.s.) or aetiology (n.s.). The median follow-up was 22 months for the TruFit cohort and 30 months for the mosaicplasty group. There was no significant difference in the requirement for re-operation (n.s). Patients undergoing autologous mosaicplasty had a higher rate of returning to sport (p = 0.006), lower EQ-5D pain scores (p = 0.048) and higher KOOS activities of daily living (p = 0.029) scores. Sub-group analysis showed no difference related to the number of cases the surgeon performed. Patients requiring re-operation had lower outcome scores regardless of their initial procedure.

Conclusion

This study demonstrated significantly better outcomes using two validated outcome scores (KOOS, EQ-5D), and an ability to return to sport in those undergoing autologous mosaicplasty compared to those receiving TruFit plugs.

Level of evidence

IV.     

Clinical and MRI evaluation of medium- to long-term results after autologous osteochondral transplantation (OCT) in the knee joint

Purpose

Autologous osteochondral transplantation (OCT) is one of the surgical options currently used to treat cartilage defects. It is the only cartilage repair method that leads to a transfer of hyaline cartilage repair tissue. The purpose of this study was to evaluate the magnetic resonance observation of cartilage repair tissue (MOCART) score, the 3D MOCART score and various clinical scores in patients after OCT in knee joints.

Methods

Two women and eight men were evaluated 6–9 years (median 7.2 years) after OCT on the femoral condyle of the knee joint. All patients were evaluated by magnetic resonance imaging (MRI) measurement, using a 3.0 T Scanner with different cartilage-specific sequences. Clinical assessment included the knee injury and osteoarthritis outcome score (KOOS), the international knee documentation committee (IKDC) subjective knee form, the Noyes sport activity rating scale and the Tegner activity score. For MRI evaluation, the MOCART score and 3D MOCART score were applied.

Results

Clinical long-term results after OCT showed median values of 77 (range 35.7–71.4) for the IKDC; 50 (6.3–100), 66.7 (30.6–97.2), 65 (0–75), 57.1 (35.7–71.4) and 80.9 (30.9–100) for the KOOS subscales (quality of life, pain sports, symptoms and activity of daily living); 61.4 (22.3–86.2) for the Noyes scale; and 3 (0–6) for the Tegner activity score. The median MOCART score was 75 (30–90) after both 1 and 2 years and 57.5 (35–90) after 7 years, as assessed by different cartilage-specific sequences. The 3D MOCART score showed values of 70 (50–85) and 60 (50–80) in the two different isotropic sequences after 7 years.

Conclusion

The MOCART and 3D MOCART scores are applicable tools for patient follow-up after OCT. Post-operative follow-up assessments would also benefit from the inclusion of OCT-specific parameters. Long-term results after OCT reflect an impairment in clinical scores in the first 2 years with good results during follow-up. Stable conditions were observed between 2 and 7 years after surgery. The filling of the defects and the cartilage interface appeared good at MRI evaluation after the first 2 years, but cartilage loss was observed between the medium- and long-term follow-ups. Isotropic imaging with multiplanar reconstruction is useful for daily clinical use to assess bony cylinders in cartilage repair, especially in combination with the 3D MOCART.

Level of evidence

Retrospective therapeutic study, Level IV.     

Platelet-rich plasma intra-articular injections for cartilage degeneration and osteoarthritis: single- versus double-spinning approach

Purpose

To compare the safety and efficacy of two different approaches of platelet-rich plasma (PRP) production methods as intra-articular injection treatment for knee cartilage degenerative lesions and osteoarthritis (OA).

Methods

The study involved 144 symptomatic patients affected by cartilage degenerative lesions and OA. Seventy-two patients were treated with 3 injections of platelet concentrate prepared with a single-spinning procedure (PRGF), the other 72 with 3 injections of PRP obtained with a double-spinning approach. The patients were evaluated prospectively at the enrollment and at 2, 6, and 12 months’ follow-up with IKDC, EQ-VAS and Tegner scores; adverse events and patient satisfaction were also recorded.

Results

Both treatment groups presented a statistically significant improvement in all the scores evaluated at all the follow-up times. Better results were achieved in both groups in younger patients with a lower degree of cartilage degeneration. The comparative analysis showed similar improvements with the two procedures: in particular, IKDC subjective evaluation increased from 45.0 ± 10.1 to 59.0 ± 16.2, 61.3 ± 16.3, and 61.6 ± 16.2 at 2, 6, and 12 months in the PRGF group, and from 42.1 ± 13.5 to 60.8 ± 16.6, 62.5 ± 19.9, and 59.9 ± 20.0 at 2, 6, and 12 months in the PRP group, respectively. Concerning adverse events, more swelling (P = 0.03) and pain reaction (P = 0.0005), were found after PRP injections.

Conclusions

Although PRP injections produced more pain and swelling reaction with respect to that produced by PRGF, similar results were found at the follow-up times, with a significant clinical improvement with respect to the basal level. Better results were achieved in younger patients with a low degree of cartilage degeneration.

Level of evidence

II.     

Is gender influencing the biomechanical results after autologous chondrocyte implantation?

Purpose

The influence of gender on the biomechanical outcome after autologous chondrocyte implantation (ACI) including isokinetic muscle strength measurements has not been investigated. The present prospective study was performed to evaluate gender-specific differences in the biomechanical function 48 months after ACI.

Methods

Fifty-two patients (mean age 35.6 ± 8.5 years) that met our inclusion criteria, underwent ACI with Bioseed C^® and were evaluated with the KOOS score preoperatively, 6, 12 and 48 months after surgery. At final follow-up, 44 out of the 52 patients underwent biomechanical evaluation with isokinetic strength measurements of both knees. All data were evaluated separately for men and women and compared for each time interval using the Mann–Whitney U test.

Results

Clinical scores improved significantly over the whole study period (p < 0.05). Male patients demonstrated significantly better scores during the follow-up in the KOOS score (p < 0.05). Isokinetic strength measurements after 48 months revealed a significant strength deficit of the treated knee in all test modes compared to the healthy extremity (p < 0.05). Furthermore, male patients achieved significantly higher strength values compared to female patients (p < 0.05).

Conclusions

ACI is a viable treatment option for full-thickness chondral defects in the knee of both genders. Isokinetic muscle strength measures are significantly worse in women (p < 0.05), but physiological and may play a role for the explanation of gender-specific results after ACI.

Level of evidence

II.     

Xenotransplantation of human mesenchymal stem cells for repair of osteochondral defects in rabbits using osteochondral biphasic composite constructs

Purpose

The aim of this work is to investigate the feasibility of non-autologous transplantation of human mesenchymal stem cells (hMSCs) with or without differentiation for the regeneration of osteochondral defects in rabbits using a biphasic composite construct composed of platelet-rich fibrin glue (PR-FG) and hydroxyapatite.

Methods

After isolation and culture, hMSCs were seeded on biphasic composite constructs (hydroxyapatite + PR-FG) and transplanted into osteochondral defects of adult New Zealand white rabbits. Treatment of individual defects was applied by random assignment to one of five groups: (1) control, defects untreated; (2) hydroxyapatite, defects filled with hydroxyapatite only; (3) hydroxyapatite + PR-FG, defects filled with a composite of hydroxyapatite and PR-FG; (4) hydroxyapatite + PR-FG + undifferentiated hMSCs; and (5) hydroxyapatite + PR-FG + differentiated hMSCs. Rabbits were killed at 4 or 8 weeks post-surgery, at which time osteochondral repair was macroscopically and histologically evaluated and scored using the modified International Cartilage Repair Society scoring system.

Results

The group in which defects were seeded with differentiated hMSCs (group 5) showed superior healing of osteochondral defects based on macroscopic and histological observations compared to other groups. Specifically, 8 weeks after implantation, defects were filled with more hyaline-like cartilage and were better integrated with the surrounding native cartilage. The histological scores were significantly better than those of other groups (16.3 at 8 weeks, p < 0.01).

Conclusion

Xenogeneic transplantation of differentiated hMSCs using a biphasic composite construct effectively repaired osteochondral defect in a rabbit model. Differentiated hMSCs showed superior healing of chondral lesion to undifferentiated hMSCs.     

Cell-free repair of small cartilage defects in the Goettinger minipig: which defect size is possible?

Purpose

Cartilage repair of full-thickness chondral defects in the knees of Goettinger minipigs was assessed by treatment with cell-free collagen type-I gel plugs of three different sizes.

Methods

In 6 adult Goettinger minipigs, three full-thickness chondral defects were created in the trochlear groove of one knee of the hind leg. These defects were treated with a cell-free collagen type-I gel plug of 8, 10, or 12 mm diameter. All animals were allowed unlimited weight bearing. After 1 year, the animals were killed. Immediately after recovery, a non-destructive biomechanical testing was performed. The repair tissue quality was evaluated immunohistologically, collagen type-II protein was quantified, and a semiquantitative score (O’Driscoll score) was calculated.

Results

After 1 year, a high number of cells migrated into the initially cell-free collagen gel plugs and a hyaline-like repair tissue had been created. The O’Driscoll scores were: 8 mm, 21.2 (SD, 2.8); 10 mm, 21.5 (SD, 1.6); and 12 mm, 22.3 (SD, 1.0). The determination of the e-modulus, creep and relaxation revealed that mechanical properties of the two smaller defects were closer to unaffected hyaline cartilage.

Conclusions

As cell-free collagen type-I gel plugs of all three different sizes created hyaline-like repair tissue, this system seems suitable for the treatment of even larger defects.     

Use of cell-free collagen type I matrix implants for the treatment of small cartilage defects in the knee: clinical and magnetic resonance imaging evaluation

Purpose

Articular cartilage defects of the knee are a common condition for which several repair techniques have been described. The aim of the present study was to assess medium-term results of a one-step procedure using a cell-free collagen type I matrix.

Methods

Fifteen patients with articular cartilage defects of the knee were treated with an 11-mm-diameter cell-free collagen type 1 matrix implant. The matrices were implanted in a press-fit manner into the defect after careful debridement down to the subchondral bone but without penetration of this margin. Follow-up examinations were carried out at 6 weeks, 6 months, and at 12, 24, 36, and 48 months after implantation. Clinical assessment included the visual analogue scale (VAS), the Tegner activity scale, and the International Knee Documentation Committee (IKDC) score. Radiological assessment for graft attachment and tissue regeneration was performed using the magnetic observation of cartilage repair tissue (MOCART) score.

Results

A total of 15 patients (males: n = 6 and females: n = 9) with a mean age of 26.4 years (range 19–40) were treated. The mean VAS improved significantly when compared to the preoperative values (P < 0.05). Six weeks after implantation, IKDC values were slightly lower than the preoperative values (n.s.), but increased significantly at final follow-up (P < 0.05). At 24 months, there were no significant differences in the median Tegner score between the post-operative values and the preoperative values (n.s.). However, after 36 months, a significant improvement was noted that lasted at least up to 48 months (P < 0.05). The MOCART score improved consistently up to 4 years after implantation, with significant improvements already observed after 12 months (P < 0.05). No correlation between the clinical scores and the MOCART score could be perceived.

Conclusion

The present study showed that the use of cell-free collagen type I matrix implants led to a significant and durable improvement in all the clinical and imaging scores investigated 4 years after implantation.

Level of evidence

IV.     

Microfracture technique versus osteochondral autologous transplantation mosaicplasty in patients with articular chondral lesions of the knee: a prospective randomized trial with long-term follow-up

Purpose

To compare long-term functional and radiological outcome following microfracture technique (MF) versus osteochondral autologous transplantation (OAT) mosaicplasty for treating focal chondral lesions of the knee.

Methods

Twenty-five patients (mean age 32.3 years, SD 7.7) with a full-thickness (International Cartilage Repair Society grade 3 or 4) chondral lesion of the articulating surface of the femur were randomized to either MF (n = 11) or OAT mosaicplasty (n = 14). At a median follow-up of 9.8 years (range 4.9–11.4), the patients were evaluated using Lysholm score (n = 25), Knee Injury and Osteoarthritis Outcome Score (KOOS, n = 25), isokinetic quadriceps measurement and hamstring strength measurement (n = 22) and standing radiographs (n = 23).

Results

There were no significant differences in Lysholm score, KOOS, isokinetic muscle strength or radiographic osteoarthritis between MF-treated patients and OAT mosaicplasty-treated patients at follow-up. Mean Lysholm score at follow-up was 69.7 [95 % confidence interval (CI), 55.1–84.4] for the MF group and 62.6 (95 % CI, 52.6–72.6) for the OAT mosaicplasty group.

Conclusion

At long-term follow-up, there were no significant differences between patients treated with MF and patients treated with OAT mosaicplasty in patient-reported outcomes, muscle strength or radiological outcome.

Level of evidence

Therapeutic study, Level II.     

Prosthetic inlay resurfacing for the treatment of focal, full thickness cartilage defects of the femoral condyle: a bridge between biologics and conventional arthroplasty

Purpose

Localized full thickness defects of the femoral condyle can be highly symptomatic. Treatment options for these lesions are numerous in young patients, however they become increasingly challenging in middle aged and older patients. In order to delay traditional joint replacement procedures and to provide a soft tissue and bone sparing alternative, this study assess a focal inlay resurfacing procedure.

Methods

Between 2004 and 2008, a consecutive series of 27 patients were treated with the Arthrosurface HemiCAP^? Focal Femoral Condyle Resurfacing Prosthesis and were assessed to study the clinical benefit of this procedure. Outcome measures included the KOOS, IKDC, HSS and WOMAC as well as physical and radiographic evaluation.

Results

Nineteen patients met the inclusion/exclusion criteria, 18 were available for review at a median follow-up of 34?months (range 20–57).The median age was 49?years (range 43–78). 63% had early arthritis, 5.2% localized osteonecrosis, and 31.6% had a focal traumatic full thickness defect. The follow-up total WOMAC score averaged 90.1?±?9.3, The KOOS showed very good to excellent scores in all domains and also when compared to age-matched normative data. Significant improvement was seen with the HSS Score. On IKDC examination, 83.4% had normal or nearly normal results.

Conclusion

Focal femoral condyle resurfacing demonstrated excellent results for pain and function in middle-aged, well selected patients with full thickness cartilage and osteochondral defects. Patient profiling and assessment of confounding factors, in particular mechanical joint alignment; meniscal function; and healthy opposing cartilage surfaces, are important for an individual treatment approach and successful outcomes.

Level of evidence

IV.     

Favourable long-term functional and radiographical outcome after osteoautograft transplantation surgery of the knee: a minimum 10-year follow-up

Purpose

The aim of this study was to assess the progression of radiological cartilage changes and to document the functional, long-term results during a follow-up of 10 years after osteoautograft transplantation (OAT) knee surgery.

Methods

The study was a retrospective analysis of all patients who underwent OAT at Turku University Hospital from 1999 to 2007. Pre- and postoperative cartilage changes were estimated based on standardised radiographs. The extent of osteoarthritis (OA) was graded according to the Kellgren–Lawrence scale. Clinical outcomes were evaluated with the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire.

Results

A total of 60 patients (64 knees) with a median age of 30 years (range 14–62) were included. The median follow-up was 140 months (range 47–205). Of the 64 knees examined, 14 (22%) had a traumatic chondral lesion and 50 (78%) had osteochondritis dissecans (OCD). Preoperatively, 71% of the patients had Kellgren–Lawrence grades of 0–1; during the follow-up period, 50% of the patients showed radiographical progression of OA. OA progressed most significantly in patients with normal preoperative Kellgren–Lawrence grades (p?=?0.0003). Patients with no progression in joint space narrowing had statistically significantly better overall KOOS (p?=?0.02) than patients whose Kellgren–Lawrence grades worsened. Patients with defect sizes?>?3.0 cm² scored statistically significantly better in all subscales than patients with smaller defect sizes (p?=?0.02). Patients with OCD had statistically significantly better KOOS than patients with chondral defects (p?=?0.008).

Conclusions

OAT surgery for treating patients with cartilage defects of the knee had good clinical results after a mean follow-up of 11 years. Radiological analyses revealed a progression of cartilage degeneration in 50% of the operated knees. Patients with no progression of the degenerative changes scored statistically significantly better on the KOOS self-assessment test. These results indicate that OAT surgery appears to be a reasonable therapeutic option to restore knee function in patients with cartilage lesions.

Level of evidence

IV.

     

One-step osteochondral repair with cartilage fragments in a composite scaffold

Purpose

This study proposes a single-step therapeutic approach for osteochondral defects using autologous cartilage fragments loaded onto a scaffold composed of a hyaluronic acid (HA) derivative, human fibrin glue (FG) and autologous platelet-rich-plasma (PRP), in a rabbit model. The aim is to demonstrate the in vitro outgrowth of chondrocytes from cartilage fragments and the in vivo formation of a functional repair tissue.

Methods

In vitro: minced articular cartilage was loaded onto two different types of scaffold (paste or membrane) according to two different HA preparations (injectable HA-derivative or HA-derivative felt). In vivo: trochlear osteochondral defects were created in 50 adult rabbits, which were then assigned to 5 different treatment groups: cartilage fragments loaded onto membrane scaffolds with FG (Group 1) or without FG (Group 2); membrane scaffolds alone with FG (Group 3) or without FG (Group 4); empty defects (Group 5). Membrane scaffolds were used “in vivo” for simpler preparation and better adhesive properties. Repair processes were evaluated histologically and by immunohistochemistry at 1, 3, and 6 months.

Results

An in vitro time-dependent cell outgrowth from cartilage fragments was observed with both types of scaffolds. At 6 months, in vivo, cartilage fragment-loaded scaffolds induced significantly better repair tissue than the scaffold alone using histological scoring. Repair in Group 2 was superior to that in any of the control groups (p < 0.05).

Conclusion

Autologous cartilage fragments loaded onto an HA felt/FG/PRP-scaffold provided an efficient cell source, and allowed for an improvement of the repair process of ostechondral defects in a rabbit model. Human FG, however, hampered the rabbit healing process. These results may have clinical relevance as they show the potential of a novel one-stage repair technique for osteochondral defects.     

Can TKA design affect the clinical outcome? Comparison between two guided-motion systems

Purpose

In a retrospective comparative analysis in patients undergoing primary guided-motion total knee arthroplasty (TKA), the authors have evaluated whether different TKA implant design would influence the clinical and functional outcomes.

Methods

Between 2007 and 2009, 227 computer-assisted primary TKAs were performed in 219 consecutive patients. Patients received one of the two different fixed-bearing guided-motion TKA designs assisted by navigation surgery: the Scorpio Non-Restrictive Geometry (NRG) knee system and the Journey Bi-Cruciate Stabilized (BCS) knee systems.

Results

Data were available for 180 patients (187 knees). No significant differences were observed between the two groups with respect to preoperative demographic characteristics, range of motion (ROM) and radiographic knee alignment. At a mean follow-up of 29 months, the Journey BCS group had higher mean Knee Injury and Osteoarthritis Outcome Score (KOOS) in all subscales and a greater ROM than the Scorpio NRG group. This difference was statistically significant for the KOOS subscales of pain (p = 0.007) and knee-related quality of life (p = 0.045), as well as for postoperative ROM (p = 0.018). Considering the overall complications, 1 patient of Scorpio NRG group (0.5 %) and 5 in Journey BCS (2.7 %) had stiffness. Anterior knee pain was reported in 4 cases of Scorpio NRG group (2.1 %). In the Journey BCS group were observed 2 cases (1.1 %) of frontal plane instability and 1 case (0.5 %) of synovitis pain.

Conclusions

The bearing geometry and kinematic pattern of different guided-motion prosthetic designs can affect the clinical–functional outcome and complications type in primary TKA.

Level of evidence

Clinical study, Level III.     

The effect of a six-month training program followed by a marathon run on knee joint cartilage volume and thickness in marathon beginners

Purpose

The purpose of this study was to investigate the effect of a 6-month period of intensive running followed by the participation at a marathon run on cartilage volume and thickness in knees of marathon beginners.

Methods

Ten asymptomatic marathon beginners underwent a supervised 6-month training program, which was finalized by the participation at a marathon run. Three-dimensional quantitative magnetic resonance imaging was performed before the training program (baseline measurements) and 1 day after the marathon (follow-up measurements). Cartilage volume and thickness of the medial and lateral femur, medial and lateral tibia, and patella were measured using semiautomated cartilage segmentation and three dimensional data postprocessing.

Results

Significant differences between baseline and follow-up measurements were observed at the lateral femur, where cartilage volume and thickness decreased by a mean of 3.2 ± 3.0 % (p = 0.012) and 1.7 ± 1.6 % (p = 0.010), respectively. No significant changes in cartilage volume and thickness were observed at the medial and lateral tibia, the medial femur, and the patella.

Conclusion

Significant cartilage loss was observed at the lateral femur; however, the measured values are comparable to previously reported precision errors for quantitative cartilage measurement and thus most likely not of clinical relevance. High-impact forces during long-distance running are well tolerated even in marathon beginners and do not lead to clinical relevant cartilage loss.

Level of evidence

IV.     

Short-term outcome of the second generation characterized chondrocyte implantation for the treatment of cartilage lesions in the knee

Purpose

To evaluate short-term clinical and MRI outcome of the second generation characterized chondrocyte implantation (CCI) for the treatment of cartilage defects in the knee.

Methods

Thirty-two patients aged 15–51 years with single International Cartilage Repair Society (ICRS) grade III/IV symptomatic cartilage defects of different locations in the knee were treated with CCI using a synthetic collagen I/III membrane to cover the defect. Clinical outcome was measured over 36 months by the Knee injury and Osteoarthritis Outcome Score (KOOS) and Visual Analogue Scale (VAS) for pain. Serial magnetic resonance imaging (MRI) scans of 22 patients were scored using the original and modified Magnetic resonance Observation of Cartilage Repair Tissue (MOCART) system.

Results

The patients included in this study showed a significant gradual clinical improvement after CCI. The MRI findings of this pilot study were considered to be promising. No signs of deterioration were observed. A complete or hypertrophic filling was observed in 76.5% of the cases at 24 months of follow-up. No preventive effect of an avital membrane on the occurrence of hypertrophic repair tissue was observed on MRI. Three failures were observed among the 32 patients until now (9.4%).

Conclusions

This investigation provided useful information on the efficacy of this treatment. The short-term clinical and MRI outcome are promising. Large-scale and long-term trials are mandatory to confirm the results and the reliability of this procedure.

Level of evidence

IV.     

Patients with focal full-thickness cartilage lesions benefit less from ACL reconstruction at 2–5?years follow-up

Purpose

To investigate differences in patient-reported outcome after anterior cruciate ligament (ACL) reconstruction between patients with and without a concomitant full-thickness cartilage lesion.

Methods

30 primary ACL-reconstructed patients with an isolated concomitant full-thickness cartilage lesion and 59 matched controls without cartilage lesions were identified in the Norwegian National Knee Ligament Registry and included in the present study. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was used as the outcome measure. At a median follow-up of 2.1?years (range, 2–5?years) after ACL reconstruction, 80 (90%) of the patients completed the KOOS.

Results

Preoperatively, there were no differences in KOOS between the study group and the control group. At follow-up, patients with full-thickness cartilage lesions reported significantly decreased scores compared to patients without cartilage lesions in the KOOS subscales pain (mean difference, 8.1; 95% confidence interval [CI], 0.8–15.3), activities in daily living (mean difference, 5.8; 95% CI, 0.3–11.2), sport/recreation (mean difference, 19.8; 95% CI, 5.3–34.3) and quality of life (mean difference, 17.2; 95% CI, 4.2–30.1). Patients with full-thickness cartilage lesions reported significantly less improvement from preoperative to follow-up than patients without cartilage lesions for the KOOS subscales pain (mean difference, 11.6; 95% CI, 3.2–19.9), sport/recreation (mean difference, 20.6; 95% CI, 8.1–33.1) and quality of life (mean difference, 16.3; 95% CI, 3.8–28.7).

Conclusions

ACL-injured patients with full-thickness cartilage lesions reported worse outcomes and less improvement after ACL reconstruction than those without cartilage lesions at 2–5?years follow-up.

Level of evidence

Prognostic; prospective cohort study, Level I.     

No negative effect on patient-reported outcome of concomitant cartilage lesions 5–9 years after ACL reconstruction

Purpose

To compare patient-reported outcome 5–9 years after anterior cruciate ligament (ACL) reconstruction in patients with and without a concomitant full-thickness [International Cartilage Repair Society (ICRS) grade 3–4] cartilage lesion.

Methods

This is a prospective follow-up of a cohort of 89 patients that were identified in the Norwegian National Knee Ligament Registry and included in the current study in 2007, consisting of 30 primary ACL-reconstructed patients with a concomitant, isolated full-thickness cartilage lesion (ICRS grade 3 and 4) and 59 matched controls without cartilage lesions (ICRS grade 1–4). At a median follow-up of 6.3 years (range 4.9–9.1) after ACL reconstruction, 74 (84 %) patients completed the Knee Injury and Osteoarthritis Outcome Score (KOOS), which was used as the main outcome measure. Secondary outcomes included radiographic evaluation according to the Kellgren–Lawrence criteria of knee osteoarthritis (OA).

Results

At follow-up, 5–9 years after ACL reconstruction, no statistically significant differences in KOOS were detected between patients with a concomitant full-thickness cartilage lesion and patients without concomitant cartilage lesions. Radiographic knee OA of the affected knee, defined as Kellgren and Lawrence ≥2, was significantly more frequent in subjects without a concomitant cartilage lesion (p = 0.016).

Conclusion

ACL reconstruction performed in patients with an isolated concomitant full-thickness cartilage lesion restored patient-reported knee function to the same level as ACL reconstruction performed in patients without concomitant cartilage lesions, 5–9 years after surgery. This should be considered in the preoperative information given to patients with such combined injuries, in terms of the expected outcome after ACL reconstruction and in the counselling and decision-making on the subject of surgical treatment of the concomitant cartilage lesion.

Level of evidence

Prognostic; prospective cohort study, Level I.

     

Cartilage repair using mesenchymal stem cell (MSC) sheet and MSCs-loaded bilayer PLGA scaffold in a rabbit model

Purpose

The integration of regenerated cartilage with surrounding native cartilage is a major challenge for the success of cartilage tissue-engineering strategies. The purpose of this study is to investigate whether incorporation of the power of mesenchymal stem cell (MSC) sheet to MSCs-loaded bilayer poly-(lactic-co-glycolic acid) (PLGA) scaffolds can improve the integration and repair of cartilage defects in a rabbit model.

Methods

Rabbit bone marrow-derived MSCs were cultured and formed cell sheet. Full-thickness cylindrical osteochondral defects (4 mm in diameter, 3 mm in depth) were created in the patellar groove of 18 New Zealand white rabbits and the osteochondral defects were treated with PLGA scaffold (n = 6), PLGA/MSCs (n = 6) or MSC sheet-encapsulated PLGA/MSCs (n = 6). After 6 and 12 weeks, the integration and tissue response were evaluated histologically.

Results

The MSC sheet-encapsulated PLGA/MCSs group showed significantly more amounts of hyaline cartilage and higher histological scores than PLGA/MSCs group and PLGA group (P < 0.05). In addition, the MSC sheet-encapsulated PLGA/MCSs group showed the best integration between the repaired cartilage and surrounding normal cartilage and subchondral bone compared to other two groups.

Conclusions

The novel method of incorporation of MSC sheet to PLGA/MCSs could enhance the ability of cartilage regeneration and integration between repair cartilage and the surrounding cartilage. Transplantation of autologous MSC sheet combined with traditional strategies or cartilage debris might provide therapeutic opportunities for improving cartilage regeneration and integration in humans.