Clinical outcomes after absorbable suture fixation of patellar osteochondral fracture following patellar dislocation

Suture-Bridge Fixation of Osteochondral Fractures and Osteochondritis Dissecans in the Knee: Excellent Rates of Early Lesion Stability and Osseous Union

BACKGROUND

Preservation of articular cartilage in the setting of acute or chronic injury in the adolescent and young adult knee is paramount for long-term joint health. Achieving osseous union, minimizing implant-related injury, and eliminating the need for reoperation for traumatic chondral and osteochondral lesions (OCLs) and osteochondritis dissecans (OCD) remain a challenge for the orthopaedic surgeon.

PURPOSE

To evaluate radiographic healing, patient-reported outcomes, and short-term complications after suture-bridge fixation of chondral fragments, osteochondral fractures, and OCD lesions in the knee.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The study included consecutive patients (38 patients, 40 knees) treated within a single academic sports medicine institution who underwent suture-bridge fixation of an OCL or an OCD lesion of the knee from initiation of the technique in October 2019 through March 2021. The suture-bridge technique entailed bioabsorbable knotless anchors placed on the outside margins of the lesion with multiple strands of hand-tensioned absorbable (No. 0 or No. 1 Vicryl) or nonabsorbable (1.3-mm braided polyester tape) bridging suture. Healing was assessed by radiography and magnetic resonance imaging (MRI), with MRI scans obtained on all OCD lesions and any chondral-only lesions. MRI scans were available for 33 of 40 (82.5%) knees within 1 year of surgery and were evaluated for lesion healing. Complications and rates and timing of return to sport were evaluated. Patient-reported outcomes in the OCD cohort were evaluated with the Knee injury and Osteoarthritis Outcome Score (KOOS) to determine early pain and functional improvement.

RESULTS

In total, 33 (82.5%) lesions demonstrated full union, and no lesions failed treatment. MRI assessment of healing (mean, 5.8 months; range, 3-12 months) demonstrated 9 (64.3%) OCD lesions with full union, 5 (35.7%) OCD lesions with stable union, and no OCD lesions with nonunion. Of the OCLs, 17 (89.5%) had full union, 2 (10.5%) had stable union, and none had nonunion. The 7 bony OCLs without an MRI scan demonstrated complete radiographic union. In 30 (75.0%) lesions, patients returned to sports at a mean of 6.5 months (range, 3.8-10.2 months). KOOS Activities of Daily Living, Pain, Quality of Life, and Symptoms scores demonstrated significant improvement from baseline at 6 months and at 1 year. There were 2 (5%) complications, consisting of reoperation for marginal chondroplasty on an otherwise stable lesion, and re-operation for intial un-treated patellar instability, with no reoperations for failure or revision of the suture-bridge construct.

CONCLUSION

In this series of OCLs and OCD lesions of the knee, suture-bridge fixation demonstrated excellent rates of MRI and radiographic union and good early outcomes with minimal short-term complications. This technique may be used for lesion salvage as an alternative to metallic and nonmetallic screw/tack constructs in the treatment of these challenging lesions. Longer term follow-up and investigation are warranted.

Medial Patellofemoral Ligament Tear Associated with an Intra-articular Axial Spilt Osteochondral Fracture of the Lateral Femoral Condyle: a "Knee Trap-door" Fracture

Introduction

Medial patellofemoral ligament (MPFL) prevents lateral dislocation of the patella and acts as a major stabilizer. The tear could be associated with osteochondral avulsion fractures; however, intra-articular split fractures are not seen. Here, we present one unusual case of such a presentation.

Case Report

A 16-year-old male presented with a history of recurrent patellar dislocation and inability to bear weight following the last episode. The patient was diagnosed with an MPFL tear with an unusual intra-articular femoral condyle split fracture. The case had significant improvement in functional scores post-surgery.

Conclusion

In physically active populations, twisting of the knee could result in an MPFL tear, leading to recurrent patellar dislocation. The treatment remains ligament reconstruction, open, or arthroscopic. Associated intra-articular fractures are very rare with such injuries and need to be addressed due to the high rate of non-union.

The influence of primary treatment approach on outcomes in patients with osteochondral fracture after patellar dislocation: a case series

BACKGROUND

We characterized the relation of primary treatment approaches to the need of later surgical interventions and the outcomes of patellar dislocation in patients with patellofemoral osteochondral fracture (OCF).

METHODS

Overall, 134 patients with OCF were categorized in two groups according to treatment approach: primary surgery (operation within 90 days from injury) and conservative treatment. Data on surgical procedures, OCF characteristics, and patellofemoral anatomy were retrospectively collected. To measure subjective outcomes, 54 patients completed the knee-specific patient-reported outcome measures (PROMs) Kujala score, Tegner activity scale, the knee injury and osteoarthritis outcome score (KOOS) quality of life (QoL) subscale, and visual analog scale pain items.

RESULTS

The mean follow-up time was 4.9 years [standard deviation (SD) 2.7 years]. The primary treatment approach was surgery in 73 patients (54%) and conservative in 61 patients (46%) of whim 18 (30%) needed late surgery. Of primary surgery patients, the OCF was reimplanted in 45 patients (62%) and removed in the rest. Of all patients, 31 needed surgery in the later phase after the primary treatment approach (either reoperation or surgery after insufficient outcome of conservative treatment). In conservatively treated patients, OCF was smaller and patellofemoral joint malformation was more severe than in surgery group. Among patients who completed the PROMs, the outcomes appeared generally acceptable in both groups.

CONCLUSIONS

Although a majority of the primary treatment approaches for OCF after patellar dislocation were definitive, one-fourth of patients required surgery in the later phase. PROMs did not indicate major differences between the study groups.

Treatment of osteochondral fracture of lateral femoral condyle after patella dislocation with anchor absorbable sutures: A new surgical technique and a case report

RATIONALE

Osteochondral fracture (OCF) in weight-bearing area of lateral femoral condyle (LFC) is a rare combined injury caused by patellar dislocation.

PATIENT CONCERNS

A 15-year-old female student accidentally sprained her right knee while participating in sports activities. The patient felt pain in his right knee and limited movement. After hospitalization, the patients underwent computed tomography scan and magnetic resonance examination.

DIAGNOSIS

According to the imaging results, patellar dislocation combined with OCF of LFC was considered in diagnosis.

INTERVENTIONS

Through the lateral parapatellar approach, we reduced the osteochondral mass and bundled it with absorbable sutures of anchors.

OUTCOMES

The functional and radiographic outcome were satisfactory at 18 months after operation.

LESSONS

Anchor absorbable suture bridge fixation for this kind of OCF is not only effective, but also economical.

Medial patellofemoral ligament reconstruction with simultaneous osteochondral fracture fixation is an effective treatment for adolescent patellar dislocation with osteochondral fractures

BACKGROUND

Osteochondral fractures can occur during patellar dislocation and often require treatment. The purpose of this study is to determine the incidence of recurrent instability and second surgery following osteochondral fracture fixation with concomitant medial patellofemoral ligament reconstruction.

METHODS

A retrospective review of a cohort of 365 medial patellofemoral ligament reconstructions by a single surgeon from 2008 to 2019 was performed to identify patients who underwent simultaneous osteochondral fracture fixation with bioabsorbable nails. Demographic data, surgical details, clinical follow-up, and subsequent procedures were collected.

RESULTS

Forty medial patellofemoral ligament reconstructions with osteochondral fracture fixation were performed by a single surgeon from 2008 to 2019. The average age at surgery was 14.6 years (range 10.7-19.6 years). The average length of follow-up was 2.6 years (range 0.7-7.0 years). Eleven (28%) patients required a second surgery on the ipsilateral knee. One patient had recurrent instability and required revision medial patellofemoral ligament reconstruction and osteochondral allograft. The other 10 patients underwent a second surgery to address cartilage damage or debridement of nails. Of the four patients who required nail debridement, the average number of nails initially placed was 7 ± 1.7. This was significantly more than the patients who did not require second surgery related to nail debridement (4.1 ± 1.6, p < .05).

CONCLUSION

28% of patients required a second procedure, most of which involved debridement of unhealed portions of the osteochondral fracture. At 2.6-year follow-up, only 2% of patients had a failure of their osteochondral fracture fixation requiring a cartilage restoration procedure. Osteochondral fracture fixation in adolescents with patellofemoral instability can be effectively treated with fixation and simultaneous medial patellofemoral ligament reconstruction.

LEVEL OF EVIDENCE

level IV.

RNA-seq based integrative analysis of potential crucial genes and pathways associated with patellar instability

Patellar instability (PI) is a common knee injury in adolescents, but the crucial biomarkers and molecular mechanisms associated with it remain unclear. We established a PI mouse model and investigated PI-related changes in gene expression by RNA sequencing (RNA-seq). Differentially expressed gene (DEG) analysis and enrichment analysis were performed to identify crucial genes and pathways associated with PI. Subsequently, a protein-protein interaction, DEG-miRNA, DEG-transcription factors, and DEG-drug interaction networks were constructed to reveal hub genes, molecular mechanism, and potential drugs for PI. Finally, the reliability of the sequencing results was confirmed by real-time quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry. Upon comparison with the control group, 69 genes were differently expressed in PI, including 17 upregulated and 52 downregulated ones. The DEGs were significantly enriched in Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway and immune responses. The protein–protein interaction network identified ten PI-related hub genes, all of which are involved in the JAK/STAT signaling pathway or inflammation-related pathways. DEG-miRNA and DEG-transcription factor networks offered new insights for regulating DEGs post-transcriptionally. We also determined potential therapeutic drugs or molecular compounds that could restore dysregulated expression of DEGs via the DGIdb database. RT-qPCR results were consistent with the RNA-seq, confirming the reliability of the sequencing data. Immunohistochemistry results suggested that JAK1 and STAT3 expression was increased in PI. Our study explored the potential molecular mechanisms in PI, provided promising biomarkers and suggested a molecular basis for therapeutic targets for this condition.

Chronic Osteochondral Fractures of the Patella Managed with Open Reduction and Internal Fixation Yields Excellent Knee Function

Currently, the management of acute osteochondral fractures (OCFs) of the patella is well established. However, the management of chronic OCFs remains debatable, as it is not clear whether such lesions can be accurately reduced or whether they will reliably heal. With well proven results of open reduction and internal fixation (ORIF) with headless compression screws (HCS) for acute OCFs, the application of this technique in late presenting cases is inconclusive. Thus, we present the clinicoradiological outcome of patients with chronic osteochondral injuries managed with ORIF. Fifteen patients who underwent surgical fixation by ORIF with HCS for chronic OCFs of the patella, between February 2013 and June 2018, were retrospectively analyzed after a mean follow-up of 3.8 years (range: 2-7 years). The mode of injury, size of the osteochondral fragment, and knee range of motion along with Kujala's scoring were examined clinically and radiological assessment was done by X-rays and magnetic resonance imaging (MRI) scans. Fifteen patients (11 males and 4 females), with a mean age of 17 years with chronic OCF of patella were enrolled. Noncontact twisting injuries were the most common mode of injury seen in 86.66% of patients and postcontact injuries in two patients (13.33%). The mean time from trauma to presentation was 7 weeks (range: 6-14 weeks). The mean preoperative Kujala's score improved from 44 to 84.8 at 6 months and 92.6 at 2 years, postoperatively. Intraoperatively, the lesion was found in medial patellar facet in 12 patients and 3 had lesions in the central facet. The mean size of the lesion was 20 mm × 18 mm. Radiological union was observed in all patients, at a mean duration of 16 weeks (range: 12-20 weeks). One patient underwent implant removal 1 year after initial surgery for mechanical symptoms. ORIF of OCFs of the patella using headless cannulated screws is simple, reliable, reproducible, and provides satisfactory outcomes. This technique can be considered for fixation of fragments with adequate subchondral bone.

Surgery for patellar dislocation has evolved towards anatomical reconstructions with assessment and treatment of anatomical risk factors

PURPOSE

Increasing knowledge on the treatment of patellar dislocation has resulted in the development of new surgical techniques for patella stabilisation. National incidence and trends in surgery for patellar dislocation were examined using data from the Finnish National Hospital Discharge Register (NHDR). The hypothesis was that an increased understanding of the pathophysiology of patellar instability has increased the popularity of reconstructing damaged structures and modification of anatomical risk factors.

METHODS

Data from the years 1997-2016 were collected from the NHDR database using ICD-10 diagnostic codes and the Nomesco Classification of Surgical Procedures (NCSP) codes. Surgical procedures were categorised into subgroups representing the main surgical approaches of patellar dislocation. Total incidence of surgery for patellar dislocation and change in incidence during the study period were calculated.

RESULTS

A total of 9702 operations for patellar dislocation were performed during the study period. Median (IQR) patient age at time of primary surgery was 23 (18-34) years. The total incidence of surgeries remained stable across the study period at of 8.9 per 100,000 person-years. Incidences of ligament reconstruction, femoral osteotomies and osteochondral fragment reimplantation operations multiplied during the study period. Ligament reconstruction procedures were the most performed operations at the end of the study period.

CONCLUSION

The incidence of surgical procedures for patellar dislocation remained unchanged during the years 1997-2016. Ligament reconstruction procedures increased in popularity. Surgical techniques have shifted towards the reconstruction of damaged structures and the modification of congenital anatomical risk factors for patellar dislocation. Diversified surgical techniques have enabled the tailoring and combining of stabilizing procedures according to the patient's individual anatomy.

Characteristics of Osteochondral Fractures Caused by Patellar Dislocation

Background

Literature describing the anatomic characteristics of osteochondral fractures (OCFs) in the knee joint after patellar dislocation is scarce.

Purpose

To describe the patterns of OCFs in the knee joint after acute or recurrent patellar dislocation in a sample of patients from 2 orthopaedic trauma centers.

Study Design

Case series; Level of evidence, 4.

Methods

In this multicenter study, all patients who had International Classification of Diseases, 10th Revision, diagnostic codes S83.0 and M22.0 between 2012 and 2018 were screened. Of the 2181 patients with clinically diagnosed patellar dislocation, 1189 had undergone magnetic resonance imaging (MRI). Patients with diagnosed patellar dislocation and osteochondral fragment verified on MRI scans were included. Demographic and clinical data were collected from electronic patient records. OCF location and size were assessed from MRI scans. Results were further compared in subgroups by sex, skeletal maturity, and primary versus recurrent patellar dislocation.

Results

An OCF was detected in 134 patients with injured knees, all of whom were included in the final analysis. It occurred in the patella in 63% of patients, in the lateral femoral condyle in 34%, and in both locations in 3%. The median OCF size was 146 mm² (interquartile range, 105-262 mm²). There was no statistically significant difference in OCF size between patellar and lateral femoral condyle fractures. Patellar OCFs were more frequent in female than male patients (P = .009) and were larger after primary than recurrent dislocation (P = .040).

Conclusion

OCFs were mainly located in the medial facet of the patella and in the lateral femoral condyle, with these locations accounting for approximately two-thirds and one-third of all OCFs, respectively. Proportion of patellar OCF was higher in female than in male. Patellar OCFs may be larger after primary than recurrent dislocation.

One-Stage Osteochondral Fracture Repair Technique With Knotless Anchors and Interconnected Crossing Suture Sliding Loops for the Knee

Osteochondral fractures of the knee represent a challenging entity to manage since there are many different surgical techniques for cartilage repair or other salvage procedures. In terms of cartilage repair, several hardware devices can be used, and many of them could imply a second-stage surgery for hardware removal. The purpose of this article is to describe in detail a one-stage osteochondral fracture repair technique with knotless anchors and interconnected crossing suture sliding loops for the knee. This technique is a one-stage open or arthroscopic procedure with an unlimited number of loops configurations with no particular need for a second surgery for hardware removal, no knot damage, and without the use of bone tunnels. It can be used in different cartilage anatomic locations, such as femoral condyles, trochlea, patella, or other joints.

Clinical Results and MRI Evaluation of Patellar Osteochondral Fracture Fixation following Patellar Dislocation

Aim

The aim of the study was to analyze the clinical results and MRI scans after transpatellar osteochondral fracture fixation following patellar dislocation.

Methods

Our study group comprised 17 patients with patellar dislocation followed by osteochondral fracture of the articular surface of the patella. All patients underwent surgery where the fractured osteochondral fragments of the patella were attached using the transpatellar suture technique. The mean age at the time of surgery was 14.1 years, and the mean follow-up period was 7.5 years.

Results

The results of the patellar compression test and the apprehension test were negative in all patients. The mean Lysholm and Kujala scores were 89.2 and 89.6, respectively. The MRI scan revealed healing of the fixed fragment and restoration of the articular surface in all patients. In 16 cases, subchondral bone of the fixed fragment area was described as irregular: its articular cartilage was narrowed and not homogenous. Progressive degenerative changes were observed in the patellofemoral joint at follow-up in three patients.

Conclusions

By fixing osteochondral fragments, the patellar articular surface can be restored. The MRI scans show that the cartilage in the reconstructed surface is narrowed after a mean 7.5-year follow-up.