The Biomechanical Influence of Defected Cartilage on the Progression of Osteochondral Lesions of the Talus: A Three-dimensional Finite Element Analysis

OBJECTIVES

Osteochondral lesions of the talus (OLTs) are common injuries in the general population. Abnormal mechanical conditions applied to defected cartilage are believed to be the culprits to deteriorating OLTs. This study aims to investigate the biomechanical effects of defect size of talar cartilage on OLTs during ankle movements.

METHODS

A finite element model of the ankle joint was created based on the computed tomography images of a healthy male volunteer. Different defect sizes (S = 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, and 2.0 cm² ) of talar cartilage were modeled to simulate the progression of OLTs. Mechanical moments were applied to the model to generate different ankle movements, including dorsiflexion, plantarflexion, inversion, and eversion. The effects of varying defect sizes on peak stress and its location were evaluated.

RESULTS

The maximum stress on the talar cartilage increased as the area of the defect enlarged. Additionally, as the defect size of OLTs increased, the areas with peak stress on talar cartilage tended to move closer to where the injury was located. High stresses were present in the medial and lateral areas of the talus at the neutral position of the ankle joint. The concentrated stresses were mainly located in the anterior and posterior defect areas. The peak stress in the medial region was higher than on the lateral side. The order of peak stress from highest to lowest was dorsiflexion, internal rotation, inversion, external rotation, plantar flexion, and eversion.

CONCLUSIONS

Osteochondral defect size and ankle joint movements significantly modulate the biomechanical features of the articular cartilage in osteochondral lesions of the talus. The progression of osteochondral lesions in a talus deteriorates the biomechanical well-being of the bone tissues of the talus.

Arthroscopic defect size measurement in osteochondral lesions of the talus underestimates the exact defect size and size measurement with arthro-MRI (MR-A) and high-resolution flat-panel CT-arthro imaging (FPCT-A)

PURPOSE

The size of osteochondral lesions of the talus (OLTs) is highly relevant for their treatment. In addition to intraoperative measurement of defect size, preoperative planning by means of magnetic resonance imaging (MRI) or computed tomography (CT) is crucial.

METHODS

Four defects of different sizes and depths were created on the talar joint surface in 14 cadaver feet. All defects were evaluated, both arthroscopically and via arthrotomy with a probe. Arthro-MRI (MR-A) and high-resolution flat-panel CT arthro scans (FPCT-A) were acquired. Length, width, and depth were measured for every defect and the defect volume was calculated. To determine the exact defect size, each talar defect was filled with plastic pellets to form a cast and the casts were scanned using FPCT to create a 3D multiplanar reconstruction data set. Finally, the surgically measured values were compared with the radiological values and the exact defect size.

RESULTS

Overall, the surgically measured values (both arthroscopic and open) underestimated the exact defect size (p < 0.05). Arthroscopically determined defect length and width showed the largest deviation (p < 0.05) and underestimated the size in comparison with MR-A and FPCT-A. The FPCT-A measurements demonstrated higher correlation with both the arthroscopic and open surgical measurements than did the MR-A measurements (p < 0.05).

CONCLUSION

The exact defect size is underestimated on intraoperative measurement, in both arthroscopic and open approaches. Arthroscopic defect size measurement underestimates defect size in comparison with MR-A and FPCT-A. FPCT-A was shown to be a reliable imaging technique that allows free image reconstruction in every plane and could be considered as the new reference standard for preoperative evaluation of defect size in OLT.

Effect of the defect localization and size on the success of third-generation autologous chondrocyte implantation in the knee joint

INTRODUCTION

Femoral and patellar cartilage defects with a defect size > 2.5 cm² are a potential indication for an autologous chondrocyte implantation (ACI). However, the influence of the localization and the absolute and relative defect size on the clinical outcome has not yet been determined. The purpose of this study is to analyze the influence of the localization and the absolute and relative defect size on the clinical outcome after third-generation autologous chondrocyte implantation.

METHODS

A total of 50 patients with cartilage defects of the knee were treated with third-generation autologous chondrocyte implantation (Novocart® 3D). A match paired analysis was performed of 25 treated femoral and 25 treated patella defects with a follow-up of three years. MRI data was used to do the manual segmentation of the cartilage layer throughout the knee joint. The defect size was determined by taking the defect size measured in the MRI in relation to the whole cartilage area. The clinical outcome was measured by the IKDC score and VAS pre-operatively and after six, 12, 24, and 36 months post-operatively.

RESULTS

IKDC and VAS scores showed a significant improvement from the baseline in both groups. Femoral cartilage defects showed significantly superior clinical results in the analyzed scores compared to patellar defects. The femoral group improved IKDC from 33.9 (SD 18.1) pre-operatively to 71.5 (SD 17.4) after three years and the VAS from 6.9 (SD 2.9) pre-operatively to 2.4 (SD 2.5) after three years. In the patellar group, IKDC improved from 36.1 (SD 12.6) pre-operatively to 54.7 (SD 20.3) after three years and the VAS improved from 6.7 (SD 2.8) pre-operatively to 3.4 (SD 2.) after three years. Regarding the defect size, results showed that the same absolute defect size at med FC (4.8, range 2-15) and patella (4.6, range 2-12) has a significantly different share of the total cartilaginous size of the joint compartment (med FC: 6.7, range 1.2-13.9; pat: 18.9, range 4.0-47.0). However, there was no significant influence of the relative defect size on the clinical outcome in either patellar or femoral localization.

CONCLUSION

Third-generation autologous chondrocyte implantation in ACI-treated femoral cartilage defects leads to a superior clinical outcome in a follow-up of three years compared with patellar defects. No significant influence of the defect size was found in either femoral or patellar cartilage defects.

Effect of the defect localization and size on the success of third-generation autologous chondrocyte implantation in the knee joint

INTRODUCTION

Femoral and patellar cartilage defects with a defect size > 2.5 cm² are a potential indication for an autologous chondrocyte implantation (ACI). However, the influence of the localization and the absolute and relative defect size on the clinical outcome has not yet been determined. The purpose of this study is to analyze the influence of the localization and the absolute and relative defect size on the clinical outcome after third-generation autologous chondrocyte implantation.

METHODS

A total of 50 patients with cartilage defects of the knee were treated with third-generation autologous chondrocyte implantation (Novocart® 3D). A match paired analysis was performed of 25 treated femoral and 25 treated patella defects with a follow-up of three years. MRI data was used to do the manual segmentation of the cartilage layer throughout the knee joint. The defect size was determined by taking the defect size measured in the MRI in relation to the whole cartilage area. The clinical outcome was measured by the IKDC score and VAS pre-operatively and after six, 12, 24, and 36 months post-operatively.

RESULTS

IKDC and VAS scores showed a significant improvement from the baseline in both groups. Femoral cartilage defects showed significantly superior clinical results in the analyzed scores compared to patellar defects. The femoral group improved IKDC from 33.9 (SD 18.1) pre-operatively to 71.5 (SD 17.4) after three years and the VAS from 6.9 (SD 2.9) pre-operatively to 2.4 (SD 2.5) after three years. In the patellar group, IKDC improved from 36.1 (SD 12.6) pre-operatively to 54.7 (SD 20.3) after three years and the VAS improved from 6.7 (SD 2.8) pre-operatively to 3.4 (SD 2.) after three years. Regarding the defect size, results showed that the same absolute defect size at med FC (4.8, range 2-15) and patella (4.6, range 2-12) has a significantly different share of the total cartilaginous size of the joint compartment (med FC: 6.7, range 1.2-13.9; pat: 18.9, range 4.0-47.0). However, there was no significant influence of the relative defect size on the clinical outcome in either patellar or femoral localization.

CONCLUSION

Third-generation autologous chondrocyte implantation in ACI-treated femoral cartilage defects leads to a superior clinical outcome in a follow-up of three years compared with patellar defects. No significant influence of the defect size was found in either femoral or patellar cartilage defects.

Outcomes in omphalocele correlate with size of defect

BACKGROUND

Omphaloceles can be some of the more challenging cases managed by pediatric surgeons. Single center studies have not been meaningful in delineating outcomes due to the length of time required to accumulate a large enough series with historical changes in management negating the results. The purpose of this study was to evaluate factors impacting the morbidity and mortality of neonates with omphaloceles.

METHODS

A multicenter, retrospective observational study was performed for live born neonates with omphalocele between 2005 and 2013 at nine centers in the United States. Maternal and neonatal data were collected for each case. In-hospital management and outcomes were also reported and compared between neonates with small and large omphaloceles.

RESULTS

Two hundred seventy-four neonates with omphalocele were identified. The majority were delivered by cesarean section with a median gestational age of 37 weeks. Overall survival to hospital discharge was 81%. The presence of an associated anomaly was common, with cardiac abnormalities being the most frequent. Large omphaloceles had a significantly longer hospital and ICU length of stay, time on ventilator, number of tracheostomies, time on total parenteral nutrition, and time to full feeds, compared to small omphaloceles. Birth weight and defect size were independent predictors of survival.

CONCLUSION

This is the largest contemporary study of neonates with omphalocele. Increased defect size is an independent predictor of neonatal morbidity and mortality.

LEVEL OF EVIDENCE

Level II.

[Alternative therapy option for plastic-aesthetic treatment of defects after resection in the upper third of the facial region in the sense of subtotal scalping instead of local flap plastics]

In the presented case, the resulting defect size after resection of a dermatofibrosarcoma protuberans exceeded the treatment capability with local flaps in the region of the exposed facial skin. Through the use of conventional wound healing in combination with a meshed split-thickness skin graft, plastic aesthetic soft tissue treatment with an aesthetically satisfactory result was possible.

Preoperative sonographic evaluation of the defect size and the diaphragm rim in congenital diaphragmatic hernia - preliminary experience

BACKGROUND

Sonographic assessment before congenital diaphragmatic hernia repair has rarely been studied.

OBJECTIVE

To evaluate the accuracy of preoperative ultrasound in measuring the defect size and in anticipating the presence of a rim and thereby to determine ultrasound's usefulness in informing the surgical approach for definitive repair of congenital diaphragmatic hernia.

MATERIALS AND METHODS

We performed a retrospective review of the medical records of seven children with left congenital diaphragmatic hernia who had undergone ultrasound and definitive repair between 2014 and 2017 at our institution.

RESULTS

The estimated defect size by ultrasound to the actual defect size measured intraoperatively for each case were as follows: 23 × 25 mm to 20 × 26 mm (case 1); 23 × 30 mm to 20 × 30 mm (case 2); 43 × 25 mm to 30 × 30 mm (case 3); 21 × 23 mm to 20 × 25 mm (case 4); 19 × 24 mm to 10 × 30 mm (case 5); 32 × 33 mm to 30 × 50 mm (case 6); and almost total absence to 40 × 50 mm (case 7). Presence or absence of each part of the diaphragm rim evaluated by ultrasound was almost identical with the actual intraoperative findings. According to the ultrasound findings, we performed a successful thoracoscopic repair in cases 1-5 with relatively small defects and presence of all parts of the rim or absence of only posterolateral rim.

CONCLUSION

There was good concordance between ultrasound findings and operative findings regarding the size of the defect and presence or absence of the diaphragm rim.

Posterior shoulder dislocation with associated reverse Hill-Sachs lesion: treatment options and functional outcome after a 5-year follow up

Background

The current study describes several surgical techniques for the treatment of the reverse Hill - Sachs lesion after posterior shoulder dislocation; we also aimed to present long term results followed for a minimum of five years.

Methods

This study is a prospective case series of 17 patients who were treated in our clinic between 2008 and 2011. Patients with a defect size smaller than 25% of the articular surface were treated conservatively. An endoprosthesis of the glenohumeral joint was implanted in patients with a defect size bigger than 40%. All remaining patients were treated by a variety of operative techniques, depending on the quality of the bone and size of the defect.

Results

Twelve of seventeen patients had a defect size of the humeral articular surface between 25% and 40% with a mean age of 39 years. Depending on the defect size these patients were treated with retrograde chondral elevation, antegrade cylindrical graft or a graft of the iliac bone crest with an open approach. All the procedures showed fair results, e.g. the open approach with a graft of the iliac bone crest (2010: Dash 3.89, Constant 90.33, Rowe 86.67; 2015: Dash 2.22, Constant 92.00, Rowe 93.33).

Conclusion

The open approach is not a disadvantage for the functional outcome. The treatment algorithm should involve the superficial size of the defect as well as the depth of the defect and the time interval between the dislocation and the surgical treatment.

Trial registration

223/2012BO2, 02 August 2010.

Right versus left congenital diaphragmatic hernia - What's the difference?

BACKGROUND

Right-sided congenital diaphragmatic hernias (CDH) and bigger defect sizes have been associated with poorer outcomes.

AIM

The aim of this study was to evaluate right- and left-sided CDH in terms of size, survival, associated anomalies, and morbidity.

MATERIAL AND METHODS

We used information from a multicenter, multinational database including patients with CDH born between 2007 and 2015. All infants with data on defect side were included for this analysis. We compared differences in outcomes between right- and left-sided CDH. Further analysis on the association between side, size of the defect, and outcome was performed.

RESULTS

A total of 3754 cases of CDH were entered in the registry between January 2007 and September 2015, with an overall survival of 71%. Of those, 598 (16%) were right-sided and 3156 left-sided, with a survival rate of 67% and 72%, respectively. Right-sided CDH had a larger proportion of C and D defects (p<0.001 and 0.04, respectively). Survival rates for the same size defect were similar, independent of the side of the defect. Multivariable logistic regression analysis with survival as dependent variable identified a significant correlation with defect size, but not side.

CONCLUSIONS

The higher proportion of large defects (C & D) in right-sided CDH, not the side itself, accounts for the reported poorer survival in right-sided CDH.

LEVEL OF EVIDENCE

Level I for a prognosis study - This is a high-quality, prospective cohort study with 99% of patients followed to the study end point (death or discharge).

Factors associated with early recurrence after congenital diaphragmatic hernia repair

BACKGROUND

The purpose of this study was to identify patient and treatment characteristics associated with early (in hospital) hernia recurrence after congenital diaphragmatic hernia (CDH) repair.

METHODS

Data from the Congenital Diaphragmatic Hernia Study Group registry were queried from 2007 to 2015. Recurrence of the diaphragmatic hernia after initial repair and prior to death or discharge was determined at the time of reoperation. Minimally invasive surgery (MIS) approaches included laparoscopy or thoracoscopy, and open approaches consisted of laparotomy or thoracotomy. Multivariate regression analysis was performed.

RESULTS

Of 3984 patients, 3332 (84%) underwent CDH repair. 76 (2.3%) patients had an early recurrence. The rate of recurrence was less variable over time for patients undergoing laparotomy vs thoracoscopy (range: 1.1-3.7% vs 1.7-8.9% annually). Timing of repair, whether performed after, during, or before ECMO did not significantly alter recurrence rates (0% vs 4.2% vs 3.0%, p=0.116). Larger defect size (C: OR 4.3, 95% CI 1.2-15.4; D: OR 7.1, 95% CI 1.7-29.1) and an MIS approach (OR 3.2, 95% CI 1.7-6.0) were the only independent predictors of recurrence.

CONCLUSION

Larger defect size and an MIS approach were associated with higher rates of early recurrence, while ECMO use and timing of repair with ECMO were not.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

II.

Effect of hernia size on operative repair and post-operative outcomes after open ventral hernia repair

BACKGROUND

Ventral hernia repair (VHR) is a commonly performed operation, but analysis of patient outcomes based upon hernia size is lacking. We sought to identify differences in operative repair and post-operative morbidity and mortality after open VHR based on hernia defect size.

METHODS

Patient and operative data were retrospectively reviewed on all patients undergoing open incisional VHR between January 2008 and February 2015 by a single surgeon at the Johns Hopkins Hospital. Patient variables were described by means for continuous variables and percentages for discrete variables, with differences between groups calculated by Chi-squared analysis.

RESULTS

During the study period, 228 patients underwent open VHR during which intraoperative defect size was measured. Patients were split into four groups based upon defect size: less than 200 cm², 200-300 cm², 301-400 cm², and over 400 cm². Patients with large defects were more likely to present with a recurrent hernia (P = 0.007) and trended towards a history of wound infections (P = 0.07). Operative time was significantly longer as defect size increased (P < 0.001). Component separation was most frequently used in patients with defects 200-300 cm² in size (P = 0.001), in whom primary closure was most likely to occur. While mesh was used in almost all patients, the specific location (overlay only, underlay only, or overlay with underlay) depended on hernia size (P < 0.001). Mean length of stay increased with defect size (P < 0.001). Larger defect size was associated with increased 30-day morbidity (P = 0.03) but not readmission (P = 0.53), recurrence (P = 0.99), or mortality (P = 0.99).

CONCLUSION

Hernia defect size affects operative time and surgical technique for repair of a ventral hernia. Larger defect size is associated with increased post-operative morbidity and length of stay but not readmission, recurrence, or mortality. Hernia size greater than 400 cm² should not be a limitation to operative repair.

Computed tomographic measurements predict component separation in ventral hernia repair

BACKGROUND

Preoperative imaging with computed tomography (CT) scans can be useful in preoperative planning. We hypothesized that CT measurements of ventral hernia defect size and abdominal wall thickness (AWT) would correlate with postoperative complications and need for complex abdominal wall reconstruction (AWR).

MATERIALS AND METHODS

Patients who underwent open ventral hernia repair and had preoperative abdominal CT imagining were identified from an institutional hernia-specific surgery outcomes database at our tertiary referral hernia center. Grade III and IV hernias and biologic mesh cases were excluded. CT measures of defect size and AWT were analyzed and correlated to complications and the need for AWR techniques using univariate, multivariate, and principal component (PC) analyses. PC1 and PC2 used five AWT measures, hernia defect width, and body mass index to create a new component variable.

RESULTS

There were 151 open ventral hernia repairs included in the study. Preoperative findings included 37.7% male; age 55.3 ± 12.5 years; body mass index (BMI) 33.3 ± 7.8 kg/m(2); 60.3% were recurrent hernias with average defect width 8.5 ± 5.0 cm and area 178.3 ± 214 cm(2); AWT at umbilicus 3.5 ± 1.8 cm; and AWT at pubis 7.0 ± 3.2. Component separation was performed in 24.0% of patients and panniculectomy in 34.4%. Wound complications occurred in 13.3% patients, and 2.7% had hernia recurrence. Increasing defect width, length, and area as well as select AWT measurements were associated with increased need for component separation, concomitant panniculectomy, and higher rates of wound and total complications (all P < 0.05). Using multivariate regression, PC1 was associated with wound complications (odds ratio [OR], 1.08; 95% confidence interval [CI], 1.01-1.16); PC2 (hernia defect width) was associated with the need for component separation (OR, 1.16; 95% CI, 1.03-1.30). Hernia recurrence was not predicted by AWT or defect size (OR, 1.00; 95%CI, 0.87-1.15).

CONCLUSIONS

Preoperative CT measurements of hernia defects and AWT predict wound complications and the need for complex AWR techniques. Obtaining preoperative CT imaging should be a consideration in preoperative planning and may help with patient counseling.

Congenital diaphragmatic hernia: defect size correlates with developmental defect

PURPOSE

The aim of our study was to elucidate if the defect size reflects the magnitude of the developmental defect in patients with CDH.

METHODS

All patients recorded in the CDH Study Group registry between January 1, 2007, and December 31, 2010, and with defect classification were included in the study. They were divided according to defect size (A-D) and compared for: gestational age (GA), birth weight (BW), number of abnormal organ systems, prevalence of associated anomalies, cardiovascular malformations (CVM), chromosomal anomalies, liver in the chest, and hernia sac.

RESULTS

A total of 1350 of 1778 patients had defect classification: 173 A, 557 B, 438 C, and 182 D. Mortality rate was 0.6%, 5.3%, 22.6%, and 45.6% in group A, B, C, and D, respectively, (p<0.0001; p for trend <0.0001). GA, BW, prevalence of associated anomalies, particularly CVM, number of abnormal organ systems, and prevalence of sac were significantly different between the groups, with a significant reduction of GA, BW, and prevalence of sac. There was an increase in prevalence of associated anomalies, liver in the chest, and number of abnormal systems as the defect size increased.

CONCLUSION

Defect size is directly correlated with mortality rate, prevalence of other anomalies (particularly CVM), and number of abnormal systems, and inversely with GA, BW, and prevalence of hernia sac. The defect size may be a marker for the magnitude of developmental abnormality, thereby explaining its relationship with the outcome.

Does ventral hernia defect length, width, or area predict postoperative quality of life? Answers from a prospective, international study

BACKGROUND

The goal of this study was to determine if ventral hernia defect length, width, or area predict postoperative pain and quality of life following ventral hernia repair (VHR).

METHODS

The International Hernia Mesh Registry, a prospective database from 40 institutions worldwide, was queried for patients undergoing VHR from October 2007 to June 2012. Laparoscopic and open VHR were evaluated separately. Width and length were stratified into large, ≥10 cm and small, <10 cm, along with area as large, ≥100 cm(2) and small, <100 cm(2).

RESULTS

In total, 865 International Hernia Mesh Registry patients underwent VHR. Large defect width, length, and area had no association with hernia recurrence or reoperation in both open and laparoscopic VHR. There was a significant increase in operating room time and length of stay for large compared with small width, length, and area for open and laparoscopic VHR patients (P < 0.05). Large area was associated with increased seroma and ileus in open and laparoscopic VHR (P < 0.05). There was greater pain and activity limitation at 1 mo for large versus small width and area whether repaired laparoscopically or open (P < 0.05). When comparing large to small length, there was no difference in pain for all follow-up time points when repaired laparoscopically, but there is significantly increased odds of pain and activity limitation at 1, 6, and 12 mo when repaired open (P < 0.05).

CONCLUSIONS

Patients undergoing laparoscopic or open VHR with large defect widths and total area have a greater chance of pain and activity limitation at 1-mo follow-up, but not long term. Large defect lengths are associated with increased early and chronic discomfort in open VHR only.