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.     

Treatment of isolated chondral and osteochondral defects in the knee by autologous matrix-induced chondrogenesis (AMIC)

Purpose

The purpose of this study is to evaluate clinical and radiological outcomes of patients treated with autologous matrix-induced chondrogenesis (AMIC) for full-thickness chondral and osteochondral defects of the femoral condyles and patella.

Method

A retrospective evaluation of clinical and radiographic outcomes of patients treated with AMIC for chondral and osteochondral full-thickness cartilage defects of the knee was performed with a mean follow-up of 28.8 ± 1.5 months (range, 13–51 months).

Results

Significant improvements in clinical outcome scores (IKDC, Lysholm, Tegner, and VAS pain score) were noted. The largest improvements were seen in the osteochondral subgroup (mean age 25.9 years), whereas patients treated for chondral defects in the patellofemoral joint and on the femoral condyles improved less. Patients in all groups were generally satisfied with their results. MRI evaluation showed that tissue filling was present but generally not complete or homogenous.

Conclusions

AMIC is a safe procedure and leads to clinical improvement of symptomatic full-thickness chondral and osteochondral defects and to regenerative defect filling. The value of AMIC relative to other cartilage repair procedures and to the natural course remains undefined.

Level of evidence

Case series, Level IV.     

Use of innovative biomimetic scaffold in the treatment for large osteochondral lesions of the knee

Purpose

Large osteochondral defects involve two different tissues characterized by different intrinsic healing capacity. Different techniques have been proposed to treat these lesions with results still under discussion. The aim of the study is to evaluate the clinical outcome of 19 patients treated with a type I collagen–hydroxyapatite nanostructural biomimetic osteochondral scaffold at minimum follow-up of 2 years.

Methods

Twenty lesions, 19 patients were treated with this scaffold implantation. The lesions size went from 4 to 8 cm² (mean size 5.2 ± 1.6 cm²). All patients were clinically evaluated using the International Repair Cartilage Society score, the Tegner Score and EQ-VAS. MRI was performed at 12 and 24 months after surgery and then every 12 months and evaluated with magnetic resonance observation of cartilage repair tissue scoring scale.

Results

The IKDC subjective score improved from a mean score of 35.7 ± 6.3 at the baseline evaluation to 67.7 ± 13.4 at 12-month follow-up (p < 0.0005). A further improvement was documented from 12 to 24 months (mean score of 72.9 ± 12.4 at 24 months) (p < 0.0005). The IKDC objective score confirmed the results. The Tegner activity score improvement was statistically significant (p < 0.0005). The EQ-VAS showed a significant improvement from 3.15 ± 1.09 to 7.35 ± 1.14 (p < 0.0005) at 2-year follow-up. The lesion’ site seems to influence the results showing a better outcome in the patients affected in the medial femoral condyle.

Conclusions

The use of the MaioRegen scaffold is a good procedure for the treatment for large osteochondral defects where other classic techniques are difficult to apply. It is an open one-step surgery with promising stable results at medium follow-up.

Level of evidence

IV.     

Long-term results after microfracture treatment for full-thickness knee chondral lesions in athletes

Purpose

Microfracture is a well-established treatment procedure for chondral defects in high-demand population with good short-term results. The purpose of our study was to evaluate long-term clinical outcome of microfracture treatment in athletes with full-thickness chondral defects.

Methods

Between 1991 and 2001, 170 patients were treated with microfracture for full-thickness knee chondral lesions at our institute and 67 of them were included in this study and prospectively followed up. Sixty-one athletes (91 %) were available at final follow-up (average 15.1 years). Average lesion size was 401 ± 27 mm². Lysholm, Tegner and International Knee Documentation Committee (IKDC) (subjective–objective) scores were utilized pre-operatively and at 2-year, 5-year and final follow-up; Knee injury and Osteoarthritis Outcome Score (KOOS), visual analog scale (VAS) and Marx scores were also collected at final follow-up.

Results

IKDC, Lysholm and Tegner scores increased significantly at 2 years, but gradually deteriorated at long term; however, average scores were significantly above baseline at final follow-up. Seven patients (11 %) were considered as failures as they underwent another operation because of reinjury or persistent pain during the first 5 years. Pain and swelling during strenuous activities was reported only in nine patients by the end of 2 years and in 35 patients at final follow-up. Patients with smaller lesions (≤400 mm²) and younger patients (≤30 years) showed significantly better results in KOOS, VAS and Marx scores. Radiographs performed at final follow-up showed evidence of progression of osteoarthritis changes in 40 % of the knees, with higher rate in older patients with large or multiple lesions (p < 0.05).

Conclusions

Microfracture when applied in young patients with smaller lesions can offer good clinical results at short- and long-term follow-up; lesion size is more important prognostic factor of outcome than age. Deterioration of the clinical outcome should be expected after 2 and 5 years post-treatment, and degenerative changes are present at long-term follow-up, with higher rate in older athletes with large, multiple lesions.

Level of evidence

IV.     

Radiographic parameters associated with lateral patella degeneration in young patients

Purpose

Localized articular cartilage degeneration in the patellofemoral joint is a common but yet understudied condition in younger patients. The purpose of this paper was to determine whether there are significant differences in radiographic alignment between those with and without isolated lateral patellofemoral degeneration.

Methods

Subjects with isolated symptomatic lateral patellofemoral degeneration and control subjects with no radiographic degeneration participated in the study. Variables of interest included the Caton-Deschamps index, sulcus angle, lateral patellofemoral angle, Dejour classification of trochlear dysplasia, patella linear displacement and the tibial tubercle-trochlear groove distance.

Results

We found significant differences between the patellofemoral degeneration group versus control group, respectively, for the Caton-Deschamps index (1.12?±?0.1 vs. 1.00?±?0.1), lateral patellofemoral angle (10.6?±?4.3 vs. 16.6?±?5.5) and tibial tubercle-trochlear groove distance (16.6?±?4.0 vs. 9.0?±?4.3). However, we found no difference in the sulcus angle (141.2?±?8.2 vs. 137.0?±?6.0), patella linear displacement (3.7?±?1.9 vs. 4.0?±?1.7) or in the Dejour Classification.

Conclusion

It appears that isolated lateral patellofemoral degeneration is associated with specific radiographic indices. Even though the radiographic measures in patients with degeneration may not be considered pathologic, they are ??high normal?? and may represent a risk factor for the development of focal chondral degeneration in the lateral trochlea and patella.

Level of evidence

III.     

Correlation between apparent diffusion coefficient and viscoelasticity of articular cartilage in a porcine model

Objective

Quantitative MR imaging techniques of degenerative cartilage have been reported as useful indicators of degenerative changes in cartilage extracellular matrix, which consists of proteoglycans, collagen, non-collagenous proteins, and water. Apparent diffusion coefficient (ADC) mapping of cartilage has been shown to correlate mainly with the water content of the cartilage. As the water content of the cartilage in turn correlates with its viscoelasticity, which directly affects the mechanical strength of articular cartilage, ADC can serve as a potentially useful indicator of the mechanical strength of cartilage. The aim of this study was to investigate the correlation between ADC and viscoelasticity as measured by indentation testing.

Materials and methods

Fresh porcine knee joints (n?=?20, age 6?months) were obtained from a local abattoir. ADC of porcine knee cartilage was measured using a 3-Tesla MRI. Indentation testing was performed on an electromechanical precision-controlled system, and viscosity coefficient and relaxation time were measured as additional indicators of the viscoelasticity of cartilage. The relationship between ADC and viscosity coefficient as well as that between ADC and relaxation time were assessed.

Results

ADC was correlated with relaxation time and viscosity coefficient (R²?=?0.75 and 0.69, respectively, p?Conclusions This study found a moderate correlation between ADC and viscoelasticity in the superficial articular cartilage. Both molecular diffusion and viscoelasticity were higher in weight bearing than non-weight-bearing articular cartilage areas.     

Cell-free collagen type I matrix for repair of cartilage defects—clinical and magnetic resonance imaging results

Purpose

Several well-described techniques are available for the treatment of chondral and osteochondral defects. The aim of the study was to assess the efficacy of a single-stage procedure incorporating a new cell-free collagen type I gel for the treatment of small chondral and osteochondral defects in the knee evaluated at 2-year follow-up.

Methods

Fifteen patients were treated with a cell-free collagen type I gel matrix of 11?mm diameter. The grafts were implanted in the debrided cartilage defect and fixed by press-fit only. The clinical outcome was assessed preoperatively and at 6?weeks, and 6, 12 and 24?months after surgery using the International Knee Documentation Committee (IKDC) score, Tegner activity scale and visual analogue scale (VAS). Graft attachment rate was assessed 6?weeks postoperatively using magnetic resonance imaging (MRI). Cartilage regeneration was evaluated using the Magnetic Observation of Cartilage Repair Tissue (MOCART) score at 6, 12 and 24?months after implantation. Clinical results were correlated with MRI findings.

Results

Six male and nine female patients were included in this study, with a mean age of 26 (range: 19–40). No complications were reported. The mean VAS values after 6?weeks and the mean IKDC patient values after 6?months were significantly improved from the preoperative values (P?=?0.005 and P?=?0.009, respectively). This improvement remained up to the latest follow-up. There were no significant differences between the median preoperative and postoperative Tegner values (n.s.). Significant improvement of the mean MOCART score was observed after 12?months and remained by 24?months (P?Conclusions The present study reveals that the new method produces both good clinical and magnetic resonance imaging results. Use of press-fit only implanted grafts of a smaller diameter leads to a high attachment rate at 24-month follow-up.

Level of evidence

IV.     

Anterior cruciate ligament reconstruction with 4-strand hamstring autograft and accelerated rehabilitation: a 10-year prospective study on clinical results, knee osteoarthritis and its predictors

Purpose

Analysis of long-term clinical and radiological outcomes after anterior cruciate ligament (ACL) reconstruction with special attention to knee osteoarthritis and its predictors.

Methods

A prospective, consecutive case series of 100 patients. Arthroscopic transtibial ACL reconstruction was performed using 4-strand hamstring tendon autografts with a standardized accelerated rehabilitation protocol. Analysis was performed preoperatively and 10 years postoperatively. Clinical examination included Lysholm and Tegner scores, IKDC, KT-1000 testing (MEDmetric Co., San Diego, CA, USA) and leg circumference measurements. Radiological evaluation included AP weight bearing, lateral knee, Rosenberg and sky view X-rays. Radiological classifications were according to Ahlbäck and Kellgren & Lawrence. Statistical analysis included univariate and multivariate logistic regressions.

Results

Clinical outcome A significant improvement (p < 0.001) between preoperative and postoperative measurements could be demonstrated for the Lysholm and Tegner scores, IKDC patient subjective assessment, KT-1000 measurements, pivot shift test, IKDC score and one-leg hop test. A pivot shift phenomenon (glide) was still present in 43 (50 %) patients and correlated with lower levels of activity (p < 0.022). Radiological outcome: At follow-up, 46 (53.5 %) patients had signs of osteoarthritis (OA). In this group, 33 patients (72 %) had chondral lesions (≥grade 2) at the time of ACL reconstruction. A history of medial meniscectomy before or at the time of ACL reconstruction increased the risk of knee OA 4 times (95 % CI 1.41–11.5). An ICRS grade 3 at the time of ACL reconstruction increased the risk of knee OA by 5.2 times (95 % CI 1.09–24.8). There was no correlation between OA and activity level (Tegner score ≥6) nor between OA and a positive pivot shift test.

Conclusion

Transtibial ACL reconstruction with 4-strand hamstring autograft and accelerated rehabilitation restored anteroposterior knee stability. Clinical parameters and patient satisfaction improved significantly. At 10-year follow-up, radiological signs of OA were present in 53.5 % of the subjects. Risk factors for OA were meniscectomy prior to or at the time of ACL reconstruction and chondral lesions at the time of ACL reconstruction.

Level of evidence

II.     

Partial meniscectomy provides no benefit for symptomatic degenerative medial meniscus posterior root tears

Purpose

Medial meniscus posterior root tears (MMPRTs) are recognized as a source of pain and dysfunction, but treatment options remain a challenge. The purpose of the study was to determine (1) the efficacy of partial meniscectomy to treat MMPRTs compared to a matched group of non-operatively treated MMPRTs, and (2) risk factors for worse clinical and radiographic outcome.

Methods

This retrospective comparative study was performed to include patients with complete, isolated MMPRTs with documented clinical symptoms and were treated with arthroscopic partial meniscectomy (PMM) and a minimum 2-year follow-up. These patients were then matched by age, gender, and BMI to patients with the same diagnosis who were treated non-operatively. Clinical and radiographic outcomes were compared between the two groups. Analysis was performed to determine risk factors for worse clinical and radiographic outcome in the PMM group alone.

Results

Overall, 52 patients were included in the study. Twenty-six patients (9M:17F) with a mean age of 55?±?9 and a mean BMI of 32.8?±?5.3 were treated with PMM and followed for 5.5?±?2.0 years (range 2.3–9.3 years). In the PMM group, final median Tegner score was 3, mean IKDC score was 67.8?±?20, and more patients had grade II or higher arthritis at final follow-up than baseline (91.3 vs. 36%, p?<?0.01). Overall, 14 of the 26 patients (54%) treated operatively progressed to total knee arthroplasty at a mean of 54.3 months. There was no significant difference in final Tegner scores, IKDC, K-L grades, progression to arthroplasty, or overall failure rate between the PMM group and non-operative group. Following PMM, female patients had lower final IKDC scores (44.0?±?2.8 vs. 74.6?±?16.7, p?=?0.02) compared to males, as well as a higher rate of arthroplasty (70.6 vs. 20.0%, p?=?0.009). Higher BMI correlated with lower IKDC scores (r?=??0.91, p?=?0.01) and meniscal extrusion was associated with higher rate of arthritis at final follow-up (p?=?0.02).

Conclusion

Partial meniscectomy for a complete MMPRT provides no benefit in halting arthritic progression. Patients who undergo PMM for MMPRTs still progress to significant arthritis, poor clinical outcomes and a high arthroplasty rate (54%) at over 5-year follow-up. Female gender, increased BMI, and meniscus extrusion were associated with worse outcome.

Study design

Level III.

     

Arthroscopically assisted retrograde drilling for osteochondritis dissecans (OCD) lesions of the knee

Purpose

Accurate retrograde drilling for osteochondritis dissecans lesions remains technically challenging. A novel, radiation-free method using an electromagnetic guidance system was developed, and its feasibility and accuracy for retrograde drilling procedures evaluated in an experimental setting.

Methods

Sixteen arthroscopically assisted, electromagnetically guided retrograde drilling procedures were performed in 4 human cadaveric knee joints. Therefore, two artificial cartilage lesions were set consecutively on each condyle. Final drill bit position was documented in two planes using fluoroscopy. Subsequently, drilling accuracy was measured in terms of distance from the final position of the drill bit to the articular cartilage surface (D1), and distance between the tip of the drill bit to the centre of the cartilage lesion on the articular cartilage surface (D2). All procedures were timed using a stopwatch.

Results

Successful retrograde drilling was accomplished in all 16 cases. The overall mean time for the retrograde drilling procedures was 361.6?±?34.7?s. Mean D1 was 2.2?±?0.5?mm; mean D2 was 0.8?±?0.7?mm. No complications occurred.

Conclusions

The novel electromagnetic guidance system used in this study showed accurate targeting results, required no radiation, was associated with no complications and demonstrated user-friendliness.

Level of evidence

II.     

The application of T1 and T2 relaxation time and magnetization transfer ratios to the early diagnosis of patellar cartilage osteoarthritis

Objectives

We compare the T1 and T2 relaxation times and magnetization transfer ratios (MTRs) of normal subjects and patients with osteoarthritis (OA) to evaluate the ability of these techniques to aid in the early diagnosis and treatment of OA.

Materials and methods

The knee joints in 11 normal volunteers and 40 patients with OA were prospectively evaluated using T1 relaxation times as measured using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), T2 relaxation times (multiple spin-echo sequence, T2 mapping), and MTRs. The OA patients were further categorized into mild, moderate, and severe OA.

Results

The mean T1 relaxation times of the four groups (normal, mild OA, moderate OA, and severe OA) were: 487.3?±?27.7, 458.0?±?55.9, 405.9?±?57.3, and 357.9?±?36.7 respectively (p?<0.001). The mean T2 relaxation times of the four groups were: 37.8?±?3.3, 44.0?±?8.5, 50.9?±?9.5, and 57.4?±?4.8 respectively (p?<?0.001). T1 relaxation time decreased and T2 relaxation time increased with worsening degeneration of patellar cartilage. The result of the covariance analysis showed that the covariate age had a significant influence on T2 relaxation time (p?<?0.001). No significant differences between the normal and OA groups using MTR were noted.

Conclusion

T1 and T2 relaxation times are relatively sensitive to early degenerative changes in the patellar cartilage, whereas the MTR may have some limitations with regard to early detection of OA. In addition, The T1 and T2 relaxation times negatively correlate with each other, which is a novel finding.     

Autologous collagen-induced chondrogenesis technique (ACIC) for the treatment of chondral lesions of the talus

Purpose

Autologous collagen-induced chondrogenesis technique (ACIC) combines microfractures with the use of an injectable atelocollagen matrix that allows performing the whole cartilage repair treatment arthroscopically. The aim of this study was to evaluate the in vitro cytocompatibility of this biomaterial using human bone marrow mesenchymal stem cells and human chondrocytes. Moreover, the preliminary data of five patients affected by chondral lesion of the talus treated with the ACIC technique are shown.

Methods

Human bone marrow mesenchymal stem cells and human chondrocytes were seeded on solid and pre-solid atelocollagen scaffolds. Cell–scaffold constructs were cultured for 7 days and then prepared for histological analyses. Arthroscopic ACIC was performed in five patients affected by chondral lesions of the talus; they were clinically evaluated with AOFAS, VAS and Tegner score before and then after 6 months from surgery.

Results

In vitro results showed that both bone marrow mesenchymal stem cells and chondrocytes were able to efficiently colonize the whole construct, from the surface to the core, only when seeded on the pre-solid atelocollagen scaffold, but not on its solid form. No adverse events were observed in the patients treated with the ACIC technique; a significant improvement in VAS pain scale and in AOFAS score was found at 6 months follow up.

Conclusion

Injectable atelocollagen can be considered a feasible scaffold for cartilage repair treatment, in particular if used in its pre-solid form. ACIC leads to good clinical results in the treatment for chondral lesions of the talus even if longer follow-up and a higher number of patients are necessary to confirm these data.

Level of evidence

IV.     

Lateral release and medial plication for recurrent patella dislocation

Purpose

This study aims to report the long-term results of lateral release and medial plication in patients with recurrent patellar dislocation.

Methods

In this study, 31 patients who underwent surgery for recurrent patellar dislocation were retrospectively reviewed between 1994 and 2004. Among the 31 patients were 12 male and 19 female patients. The average age was 23.9?±?4.8?years, and the mean follow-up period was 11.6?±?2.4?years.

Results

Three patients had postoperative dislocations. The mean Kujala score significantly improved from 57.5?±?13.2 points preoperatively to 89.2?±?8.7 points at the final follow-up (P?<?0.0001). The median Tegner activity score significantly improved from 3 (range, 1?C5) at preoperative examination to 7 (range, 3?C9) at the final follow-up (P?<?0.0001). Ten patients were rated as excellent, 18 as good, 2 as fair, and 1 as poor. The congruence angle improved from 16.5°?±?3.0° to ?2.8°?±?2.7°, and the lateral patellofemoral angle improved from ?4.2°?±?1.9° to 8.2°?±?2.5°. There was no case of osteoarthritis at the final follow-up.

Conclusions

Percutaneous lateral release and medial plication showed satisfactory results with limited morbidity in the long-term follow-up. This traditional method remains a simple and effective surgical procedure for recurrent patellar dislocation.

Level of evidence

Therapeutic, Level IV.     

Combined distal femoral osteotomy (DFO) in genu valgum leads to reliable patellar stabilization and an improvement in knee function

Purpose

Valgus deformities of the lower extremity influence patellofemoral joint kinematics. However, studies examining the clinical outcome after treatment of patellar instability and maltracking due to valgus deformity are rare in recent literature. This study’s purpose is to analyze the clinical results after combined distal femoral osteotomy (DFO) for treatment of patellar instability.

Methods

From 2010 to 2016, 406 cases of patellofemoral instability and maltracking were treated. Twenty cases of recurring (≥?2) patellar dislocations with genu valgum and unsuccessful conservative treatment were included in the study. A radiological analysis was performed, and anteroposterior (AP), lateral and long leg standing radiographs were analyzed, and the leg axis was pre- and postoperatively measured. At least 12 months postoperatively, the clinical leg axis, range of motion (ROM), apprehension sign, Zohlen sign, and J-sign were physically examined. Pain level and knee function were objectified on a visual analogue scale (VAS). The Lysholm, Kujala, and Tegner scores, re-dislocation rate, and patient satisfaction were also examined.

Results

20 combined DFOs on 18 patients with a median age of 23 years (15–55 years) were performed. The preoperative mechanical leg axis was 6.5°?±?2.0° valgus, and the mean tibial tuberosity to trochlear groove (TT-TG) distance was 19.1?±?4.8 mm. All patients reported multiple dislocations. Intraoperatively, 71% presented III°–IV° cartilage lesions, located retropatellarly in 87% and correlating negatively with the postoperative Lysholm score (r?=???0.462, p?=?0.040). The leg axis was corrected by 7.1°?±?2.6°, and in 17 cases, the tibial tubercle was additionally medialized by 10?±?3.1 mm. All patellae were re-stabilized with medial patellofemoral ligament reconstruction. After a median period of 16 (12–64) months, the pain level decreased from 8.0?±?1.4 to 2.3?±?2.1 (VAS p?≤?0.001) and knee function improved from 40.1?±?17.9 to 78.5?±?16.6 (Kujala p?≤?0.001), 36.1?±?19.5 to 81.6?±?11.7 (Lysholm p?≤?0.001), and 2.0 (1–5) to 4.0 (3–6) (median Tegner p?≤?0.001). No re-dislocation was observed.

Conclusion

Combined DFO is a suitable treatment for patellar instability and maltracking due to genu valgum, as it leads to very low re-dislocation rates, a significant reduction of pain, and a significant increase of knee function with good-to-excellent results in the short-term follow-up. However, a high prevalence of substantial cartilage lesions is observed, causing postoperative limitations of knee function.

Level of evidence

IV, retrospective cohort study.

     

Treatment of severe osteochondral defects of the knee by combined autologous bone grafting and autologous chondrocyte implantation using fibrin gel

Purpose

Severe symptomatic and unstable osteochondral defects of the knee are difficult to treat. A variety of surgical techniques have been developed. However, the optimal surgical technique is still controversial. We present a novel technique in which autologous bone grafting is combined with gel-type autologous chondrocyte implantation (GACI).

Methods

Isolated severe osteochondral defects of the medial or lateral femoral condyle were treated by a two-step procedure. Firstly, chondrocytes were harvested during arthroscopy and cultured for 6?weeks. Secondly, a full thickness corticospongious autologuos bone graft, harvested from the medial or lateral femur condyle, is impacted in the defect and covered by GACI. The fibrin gel fills up to the exact shape of the chondral lesion and polymerizes within 3?min after application.

Results

From 2009 to 2011, 9 patients, median age 35?years (range 23–47), were treated by the combined autologous bone grafting and GACI technique. Median defect size was 7.1?cm² (range 2.5–12.0), and median depth of the lesion was 0.9?cm (range 0.8–1.2). Median follow-up was 9?months (range 6–12?months). Six patients were available for 12-month follow-up. The mean IKDC score showed a 6-month improvement from 35 (SD?±?16) to 51 (SD?±?18) (n?=?9; p?=?0.01), and a 1-year improvement from 35 (SD?±?16) to 57 (SD?±?20) (n?=?6; p?=?0.03). The mean KOOS improved from 44 (SD?±?16) to 62 (SD?±?19) (n?=?9; p?=?0.07) at 6-month follow-up and from 44 (SD?±?16) to 65 (SD?±?24) (n?=?6; p?=?0.1) at 12-month follow-up. There was one failure that needed conversion to a unicompartmental knee arthroplasty.

Conclusion

Combined autologous bone grafting and GACI may offer an alternative surgical option for severe and unstable osteochondral defects of the knee.

Level of evidence

IV.     

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.     

The influence of femoral tunnel position in single-bundle ACL reconstruction on functional outcomes and return to sports

Purpose

The purpose of this study was to radiographically investigate the influence of femoral tunnel placement in ACL reconstruction on early outcomes and return to sports due to anatomic and nonanatomic positioning.

Methods

A prospective study was conducted from 2008 to 2010, with 86 athletes who underwent ACL reconstruction between anteromedial (AM) footprint and high AM position. Knee functional outcomes (IKDC objective and subjective, Tegner score, and Lysholm scale) return to sports and complications were analyzed at 6- and 12-month follow-up.

Results

At follow-up, it was observed that tunnel projection along Blumensaat’s line was correlated with functional outcomes on Tegner scale (at 6 and 12 months) and IKDC subjective (at 12 months). There was a significant difference in mean tunnel projection along Blumensaat’s line when analyzing return to sports (73 ± 1.4 and 79 ± 1.7 %, respectively, for projections on return vs. no return to sports, p = 0.02) and complications (73 ± 1.3 vs. 78 ± 1.6 %, respectively, for projections on no complications vs. complications, p = 0.03). No differences were stated on coronal view. These correlations between tunnel positioning on functional outcomes could not be explained by demographic or baseline characteristics.

Conclusion

The clinical relevance of this study is that tunnel positioning along AM footprint and high AM position represented by tunnel projection along Blumensaat’s line is associated with early return to sports on previous Tegner level and better functional outcome in athletes.

Level of evidence

III.     

The safety and efficacy of magnetic targeting using autologous mesenchymal stem cells for cartilage repair

Purpose

A new cell delivery system using magnetic force, termed magnetic targeting, was developed for the accumulation of locally injected cells in a lesion. The aim of this study was to assess the safety and efficacy of mesenchymal stem cell (MSC) magnetic targeting in patients with a focal articular cartilage defect in the knee.

Methods

MSC magnetic targeting for five patients was approved by the Ministry of Health Labour and Welfare of Japan. Autologous bone marrow MSCs were cultured and subsequently magnetized with ferucarbotran. The 1.0-T compact magnet was attached to a suitable position around the knee joint to allow the magnetic force to be as perpendicular to the surface of the lesion as possible. Then 1?×?10⁷ MSCs were injected into the knee joint. The magnet was maintained in the same position for 10 min after the MSC injection. The primary endpoint was the occurrence of any adverse events. The secondary endpoints were efficacy assessed by magnetic resonance imaging (MRI) T2 mapping and clinical outcomes using the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation and the Knee Injury and Osteoarthritis Outcome Score (KOOS).

Results

No serious adverse events were observed during the treatment or in the follow-up period. Swelling of the treated knee joint was observed from the day after surgery in three of the five patients. The swelling resolved within 2 weeks in two patients. MRI showed that the cartilage defect areas were almost completely filled with cartilage-like tissue. MOCART scores were significantly higher 48 weeks postoperatively than preoperatively (74.8?±?10.8 vs 27.0?±?16.8, p?=?0.042). Arthroscopy in three patients showed complete coverage of their cartilage defects. Clinical outcome scores were significantly better 48 weeks postoperatively than preoperatively for the IKDC Subjective Knee Evaluation (74.8?±?17.7 vs 46.9?±?17.7, p?=?0.014) and knee-related quality-of-life (QOL) in the KOOS (53.8?±?26.4 vs 22.5?±?30.8, p?=?0.012).

Conclusion

Magnetic targeting of MSCs was safely performed and showed complete coverage of the defects with cartilage-like tissues and significant improvement in clinical outcomes 48 weeks after treatment. The magnetic targeting of MSCs is useful as a minimally invasive treatment for cartilage repair.

Level of evidence

IV.

     

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.     

Autologous chondrocyte implantation for the treatment of chondral and osteochondral defects of the talus: a meta-analysis of available evidence

Purpose

While autologous chondrocyte implantation (ACI) has become an established surgical treatment for cartilage defects of the knee, only little is known about the clinical outcome following ACI for chondral or osteochondral lesion of the ankle. To evaluate efficiency and effectiveness of ACI for talar lesions was aim of the present meta-analysis.

Methods

An OVID-based literature search was performed to identify any published clinical studies on autologous chondrocyte implantation (ACI) for the treatment of pathologies of the ankle including the following databases: MEDLINE, MEDLINE preprints, EMBASE, CINAHL, Life Science Citations, British National Library of Health, and Cochrane Central Register of Controlled Trials (CENTRAL). Literature search period was from the beginning of 1994 to February 2011. Of 54 studies that were identified, a total of 16 studies met the inclusion criteria of the present meta-analysis. Those studies were systematically evaluated.

Results

All studies identified represented case series (EBM Leven IV). 213 cases with various treatment for osteochondral and chondral defects with a mean size of 2.3?cm² (±0.6) have been reported. A total of 9 different scores have been used as outcome parameters. Mean study size was 13 patients (SD 10; range 2–46) with a mean follow-up of 32?±?27?months (range 6–120). Mean Coleman Methodology Score was 65 (SD 11) points. Overall clinical success rate was 89.9%.

Conclusions

Evidence concerning the use of ACI for osteochondral and chondral defects of the talus is still elusive. Although clinical outcome as described in the studies available seems promising—with regard to a lack of controlled studies—a superiority or inferiority to other techniques such as osteochondral transplantation or microfracturing cannot be estimated.