Spanish experience in autologous chondrocyte implantation

Continuous passive motion following cartilage surgery: does a common protocol exist?

Continuous passive motion (CPM) devices have the potential to improve the histological content as well as the rate and volume of chondrogenesis in repair tissue following chondral injury. However, clinical evidence is lacking to support broad implementation of CPM following cartilage restoration procedures. We searched PubMed, CINAHL, SPORTDiscus, and Cochrane for such terms as knee, continuous passive motion, CPM, ACI, ACT, autologous chondrocyte implantation, autologous chondrocyte transplantation, microfracture, marrow-stimulation technique, mosaicplasty, osteochondral autograft, and osteochondral allograft. Inclusion criteria were all English-language studies of human subjects, evidence levels I to IV, reporting the use of CPM following cartilage repair or restoration surgery in the knee. One hundred and seven studies met inclusion criteria. Sixty-three studies reported the use of CPM following autologous chondrocyte implantation; 28 reported the use of CPM following microfracture; 13 reported the use of CPM following osteochondral autograft; and 15 reported the use of CPM following osteochondral allograft (several studies reported > 1 type of cartilage procedure, which explains why the sum of all studies reporting a particular procedure [119] is greater than the number of studies included in the review [107]). Of the 5723 patients included, 60.8% were treated with autologous chondrocyte implantation, 23.1% were treated with microfracture, 6.4% were treated with osteochondral autograft, and 9.7% were treated with osteochondral allograft. Of the 6612 total defects, 5043 (76.3%) were tibiofemoral and 1569 (23.7%) were patellofemoral. Most reports of CPM use after cartilage restoration procedures did not include specific information on how it was implemented. Overall, the description of CPM protocols in published knee articular cartilage surgery studies was disappointing. The majority of studies did not describe common variables such as the duration of CPM therapy, the initiation of CPM therapy, and the initial range of motion used. The most commonly prescribed parameters within a CPM regimen are initiated on the first postoperative day, with an initial range-of-motion of 0 to 30 degrees and a frequency of 1 cycle per minute, and for 6 to 8 hours daily over 6 weeks. The lack of consistent standardized reporting of postoperative CPM protocols provides an impetus to researchers and clinicians to more clearly define and describe their use following knee articular surgery.

Cryopreservation effect on proliferative and chondrogenic potential of human chondrocytes isolated from superficial and deep cartilage

Objectives:

To compare the proliferative and chondrogenic potential of fresh and frozen chondrocytes isolated from superficial and deep articular cartilage biopsies.

Materials and Methodology:

The study included 12 samples of fresh and frozen healthy human knee articular cartilage. Cell proliferation was tested at 3, 6 and 9 days. Studies of mRNA quantification, protein expression and immunofluorescence for proliferation and chondrogenic markers were performed.

Results:

Stimulation of fresh and frozen chondrocytes from both superficial and deep cartilage with fetal bovine serum produced an increase in the proliferative capacity compared to the non-stimulated control group. In the stimulated fresh cells group, the proliferative capacity of cells from the deep biopsy was greater than that from cells from the superficial biopsy (0.046 vs 0.028, respectively, p<0.05). There was also a significant difference between the proliferative capacity of superficial zone fresh (0.028) and frozen (0.051) chondrocytes (p<0.05). CCND1 mRNA and protein expression levels, and immunopositivity for Ki67 revealed a higher proliferative capacity for fresh articular chondrocytes from deep cartilage. Regarding the chondrogenic potential, stimulated fresh cells showed higher SOX9 and Col II expression in chondrocytes from deep than from superficial zone (p<0.05, T student test).

Conclusions:

The highest rate of cell proliferation and chondrogenic potential of fresh chondrocytes was found in cells obtained from deep cartilage biopsies, whereas there were no statistically significant differences in proliferative and chondrogenic capacity between biopsy origins with frozen chondrocytes. These results indicate that both origin and cryopreservation affect the proliferative and chondrogenic potential of chondrocytes.

Failures, re-operations, and complications after autologous chondrocyte implantation--a systematic review

OBJECTIVE

To determine and compare failure, re-operation, and complication rates of all generations and techniques of autologous chondrocyte implantation (ACI).

METHODS

A systematic review of multiple medical databases was performed according to PRISMA guidelines. Levels I-IV evidence were included. Generations of ACI and complications after ACI were explicitly defined. All subject and defect demographic data were analyzed. Modified Coleman Methodology Scores (MCMSs) were calculated for all studies.

RESULTS

82 studies were identified for inclusion (5276 subjects were analyzed; 6080 defects). Ninety percent of the studies in this review were rated poor according to the MCMS. There were 305 failures overall (5.8% subjects; mean time to failure 22 months). Failure rate was highest with periosteal ACI (PACI). Failure rates after PACI, collagen-membrane cover ACI (CACI), second generation, and all-arthroscopic, second-generation ACI were 7.7%, 1.5%, 3.3%, and 0.83%, respectively. The failure rate of arthrotomy-based ACI was 6.1% vs 0.83% for all-arthroscopic ACI. Overall rate of re-operation was 33%. Re-operation rate after PACI, CACI, and second-generation ACI was 36%, 40%, and 18%, respectively. However, upon exclusion of planned second-look arthroscopy, re-operation rate was highest after PACI. Unplanned re-operation rates after PACI, CACI, second-generation, and all-arthroscopic second-generation ACI were 27%, 5%, 5%, and 1.4%, respectively. Low numbers of patients undergoing third-generation ACI precluded comparative analysis of this group.

CONCLUSIONS

Failure rate after all ACI generations is low (1.5-7.7%). Failure rate is highest with PACI, and lower with CACI and second-generation techniques. One out of three ACI patients underwent a re-operation. Unplanned re-operations are seen most often following PACI. Hypertrophy and delamination is most commonly seen after PACI. Arthrofibrosis is most commonly seen after arthrotomy-based ACI. Use of a collagen-membrane cover, second-generation techniques, and all-arthroscopic, second-generation approaches have reduced the failure, complication, and re-operation rate after ACI.