Patellofemoral Pain, Instability, and Arthritis: Clinical Presentation, Imaging, and Treatment

Preface
Acknowledgment
Contents
1: Patellofemoral Pain, Instability, and Arthritis
	1.1	 General Considerations
	1.2	 Classification
	1.3	 PF Instability
		1.3.1	 Anatomic Factors Causing PF Instability
			1.3.1.1	 Major Instability Factors
				Primary Factors Contributing to PF Instability
				Secondary Factors Contributing to PF Instability
	References
2: Genetics and Syndromes with Patellofemoral Disorders
	2.1	 Patellar Development
	2.2	 Evolution
	2.3	 Embryonic Development of the Lower Limb
	2.4	 Genetic Syndromes
	2.5	 Small Patella Syndrome
	2.6	 Nail Patella Syndrome
		2.6.1	 Radiologic Characteristics
		2.6.2	 Treatment of NPS
	2.7	 Recommendations
	References
3: Detecting and Addressing Psychological Factors
	3.1	 Introduction
	3.2	 Your Approach to Pain: What Do You Know? What Must You Know?
	3.3	 Psychological Features
	3.4	 Psychological Strategies: The Practicalities of Assessment and Treatment
	3.5	 Summary
	References
4: Imaging Analysis of Patella Instability Factors
	4.1	 Trochlear Dysplasia
	4.2	 Patellar Height
	4.3	 Tibial Tubercle-Trochlear Groove (TT-TG) Distance
	4.4	 Rotational Alignment of Femur and Tibia
	4.5	 Conclusions
	References
5: Magnetic Resonance Imaging of the Patellofemoral Articular Cartilage
	5.1	 Introduction
	5.2	 Applied Cartilage Anatomy
	5.3	 MRI Technique
	5.4	 Normal Osteochondral Unit Imaging
	5.5	 Osteochondral Lesions
	5.6	 Evaluation of Cartilage Repair Procedures
	5.7	 Conclusion
	References
6: Computed Tomography and Arthro-CT Scan in Patellofemoral Disorders
	6.1	 Exam Protocol
	6.2	 Patella Height
	6.3	 Trochlear Dysplasia
	6.4	 Tibial Tubercle-Trochlear Groove (TT-TG) Distance
	6.5	 Patellar Tilt
	6.6	 Femoral Anteversion
	6.7	 External Tibial Torsion
	References
7: The Role of Tibial and Femoral Rotational Torsion Abnormalities in the Treatment of Patellofemoral Dysfunction
	7.1	 Introduction
	7.2	 Biomechanics
	7.3	 Approach in Clinical Practice
		7.3.1	 Physical Exam
		7.3.2	 Imaging
			7.3.2.1	 Computed Tomography (CT)
			7.3.2.2	 Low-Dose Biplanar Radiography (EOS)
		7.3.3	 Gait Analysis
	7.4	 Surgical Treatment
		7.4.1	 Tibial Derotation Osteotomy
		7.4.2	 Is Fibular Osteotomy Needed?
		7.4.3	 Femoral Osteotomy Stabilization
	7.5	 Conclusion
	References
8: Pathophysiology of Anterior Knee Pain
	8.1	 Introduction
	8.2	 Theories on the Genesis of AKP
	8.3	 A Critical Analysis of Realignment Surgery for PFM
	8.4	 Is There a Mechanical Overload of the PFJ Behind the AKP? Role of Patellofemoral Imbalance in the Genesis of AKP
	8.5	 Neuroanatomical Bases for AKP in the Young Patient: Neural Model
		8.5.1	 Morphologic Neural Changes in the LR
		8.5.2	 Hyperinnervation into the LR and AKP
	8.6	 Role of Ischemia in the Genesis of AKP: Loss of Vascular Homeostasis
		8.6.1	 Basic Science
		8.6.2	 Clinical Studies
	8.7	 A Pain Neuromatrix Approach to AKP Patients: MR Resting State Functional Connectivity in AKP
	8.8	 Authors’ Proposed AKP Pathophysiology
	8.9	 Conclusions
	References
9: Patellofemoral Pain Syndrome: The Value of Single Photon Emission Computerized Tomography and Conventional Computerized Tomography (SPECT/CT)
	9.1	 Introduction
		9.1.1	 SPECT/CT Imaging
	9.2	 Conclusions
	References
10: Non-operative Treatments for Patellofemoral Arthritis
	10.1	 Introduction
	10.2	 Patellofemoral Pain Syndrome
		10.2.1	 Anatomy of the Patellofemoral Joint (PFJ)
		10.2.2	 Biomechanics and Kinematics of PFJ
		10.2.3	 Etiology of PFPS
			10.2.3.1	 Patellar Maltracking
				VMO Deficiency
				Hip Abductor and External Rotator Weakness
				Iliotibial Band Tightness
				Rear-Foot Eversion
			10.2.3.2	 Overuse
			10.2.3.3	 Aberrant Pain Pathways
			10.2.3.4	 Psychological Impact: Catastrophizing and Fear Aversion
		10.2.4	 History
		10.2.5	 Clinical Evaluation
			10.2.5.1	 Inspection
			10.2.5.2	 Palpation
			10.2.5.3	 Gait
			10.2.5.4	 Special Tests
			10.2.5.5	 Radiographic Evaluation
				Plain Radiographs
				Advanced Imaging: CT and MRI
		10.2.6	 Treatment
			10.2.6.1	 Non-operative
				Strengthening
				Gait Retraining
				Foot Orthotics
				Bracing and Taping
			10.2.6.2	 Operative
	10.3	 Additional Causes of Anterior Knee Pain
		10.3.1	 Patellar Tendinopathy
			10.3.1.1	 Pathology
			10.3.1.2	 Diagnosis
			10.3.1.3	 Treatment
		10.3.2	 Iliotibial Band Syndrome (ITBS)
			10.3.2.1	 Pathology
			10.3.2.2	 Diagnosis
			10.3.2.3	 Treatment
		10.3.3	 Lateral Patellofemoral Compression Syndrome (LPCS)
			10.3.3.1	 Pathology
			10.3.3.2	 Diagnosis
			10.3.3.3	 Treatment
		10.3.4	 Plica Syndrome
			10.3.4.1	 Pathology
			10.3.4.2	 Diagnosis
			10.3.4.3	 Treatment
		10.3.5	 Chondral Lesions
			10.3.5.1	 Pathology
			10.3.5.2	 Diagnosis
			10.3.5.3	 Treatment
	References
11: Is There a Surgical Treatment of Patellofemoral Pain?
	11.1	 Background
	11.2	 When Surgery Is Needed: General Principles
	11.3	 Minimally Invasive Surgical Procedures
	11.4	 Major Surgical Procedures: Osteotomies
		11.4.1	 Torsional Malalignment of the Lower Limb
			11.4.1.1	 Rationale
			11.4.1.2	 Clinical Evaluation
			11.4.1.3	 Measuring Torsion
			11.4.1.4	 Surgical Tips in Rotational Osteotomies
	11.5	 Conclusion
	References
12: Anatomic Instability Factors: Principals and Secondary for Patellar Instability
	12.1	 Introduction
	12.2	 Soft Tissue Abnormalities
		12.2.1	 Vastus Medialis Obliquus (VMO)
		12.2.2	 Medial Ligaments
		12.2.3	 Hyperlaxity
	12.3	 Bone Abnormalities
		12.3.1	 Trochlear Dysplasia
		12.3.2	 Patellar Dysplasia
		12.3.3	 Patellar Height
		12.3.4	 Rotational Deformities and Coronal Plane Malalignment
	12.4	 Conclusion
	12.5	 Summary
	References
13: Influence of Risk Factors in the Natural History
	13.1	 Conclusion
	References
14: History and Clinical Examination of Patellofemoral Instability
	14.1	 Clinical Symptoms
		14.1.1	 Background
		14.1.2	 Key Questions for Patients with an Initial Injury
		14.1.3	 Key Questions for Patients with a Recurrent Injury
		14.1.4	 Goals of History Taking in Patellofemoral Instability
		14.1.5	 Paediatric Patients
		14.1.6	 Older Patients
		14.1.7	 Medial Patellar Subluxation/Dislocation
	14.2	 Clinical Examination
		14.2.1	 Background
		14.2.2	 Key Points for Patients with Suspected Acute Patellar Instability: First Time or Recurrent
		14.2.3	 Key Points for Patients with Suspected Recurrent Instability: Non-acute Visit Examination
		14.2.4	 Key Points for Complex Situations or Patients with Previous Surgery
		14.2.5	 The Standard Clinical Examination for Patellofemoral Instability
		14.2.6	 Goals of the Clinical Examination in Patellofemoral Instability
	14.3	 Conclusion
	References
15: First-Time Dislocation: How to Deal with It
	15.1	 Introduction
	15.2	 Diagnosis and Assessment of Risk Factors for Recurrence
	15.3	 Nonoperative Management of First-Time Patellar Dislocation
	15.4	 Surgical Management of First-Time Patellar Dislocation
	15.5	 Review of the Current Clinical Evidence
	15.6	 Pearls How to Deal with First-Time Patellar Dislocation
	References
16: Medial Patellofemoral Anatomy: Surgical Implications in Patellofemoral Instability
	16.1	 Introduction
	16.2	 Terminology
	16.3	 Proximal Medial Patellar Restraints
	16.4	 Femoral Origin
	16.5	 Anterior Attachment
	16.6	 Distal Medial Patellar Restraints
		16.6.1	 MPTL
		16.6.2	 MPML
	16.7	 Conclusion
	References
17: Medial Retinaculum Reefing for Patellar Instability
	17.1	 Introduction
	17.2	 Materials and Methods
	17.3	 Surgical Technique
	17.4	 Results
	17.5	 Discussion
	17.6	 Conclusion
	References
18: Medial Patellofemoral Ligament (MPFL) Reconstruction
	18.1	 Introduction
	18.2	 Anatomy of the MPFL
	18.3	 Natural History
	18.4	 Patient History and Physical Findings
	18.5	 Imaging
	18.6	 Indications and Contraindications
	18.7	 Preoperative Preparation
	18.8	 Graft Options
	18.9	 Surgical Objectives
	18.10	 Authors’ Preferred Technique
		18.10.1 Setup
		18.10.2 EUA
		18.10.3 Arthroscopy
		18.10.4 Semitendinosus Tendon Harvest
		18.10.5 Patellar Exposure and Patellar Tunnels
		18.10.6 Femoral Exposure and Femoral Tunnel
		18.10.7 Postoperative Care
	18.11	 Results and Complications
		18.11.1 Pearls/Pitfalls
	References
19: Medial Patellotibial Ligament: Clinical Application and Surgical Reconstruction for Patellar Stabilization
	19.1	 Introduction
	19.2	 Biomechanics
	19.3	 Clinical
	19.4	 Surgical Considerations
		19.4.1	 Surgical Technique of MPTL Reconstruction Using Medial Third of PT
		19.4.2	 Surgical Technique of MPTL Reconstruction Using Free Hamstring Graft
	References
20: Tibial Tubercle Osteotomies: Indications and Results
	20.1	 Introduction
	20.2	 Recurrent Patellar Instability
		20.2.1	 A Changing Paradigm
		20.2.2	 Biomechanics
		20.2.3	 Indications
			20.2.3.1	 Radiological Assessment of Patellar Height
			20.2.3.2	 Radiological Assessment of Tibial Tubercle Lateralisation
			20.2.3.3 Threshold Values
			20.2.3.4 Author’s Approach
		20.2.4	 Results
			20.2.4.1	 Results of Tibial Tubercle Osteotomy Without MPFL Reconstruction
				Tibial Tubercle Medialisation
				Tibial Tubercle Anteromedialisation
			20.2.4.2	 Results of Tibial Tubercle Osteotomy Combined with MPFL Reconstruction
				Comparative Studies
				Case Series of Combined Procedures
	20.3	 Pain and Osteoarthritis
		20.3.1	 Principles
		20.3.2	 Biomechanics
		20.3.3	 Indications
			20.3.3.1 Author’s Approach
		20.3.4	 Results
			20.3.4.1	 Tibial Tubercle Anteriorisation
			20.3.4.2	 Tibial Tubercle Anteromedialisation
	20.4	 Complications
	References
21: Tibial Tubercle Anteromedialization Osteotomy
	21.1	 Introduction
	21.2	 Biomechanics
	21.3	 Evaluation
		21.3.1	 History
		21.3.2	 Physical Examination
		21.3.3	 Imaging
			21.3.3.1	 Radiographs
			21.3.3.2	 Computed Tomography and Magnetic Resonance Imaging
	21.4	 Indications
	21.5	 Contraindications
	21.6	 Surgical Technique
		21.6.1	 Preoperative Planning
		21.6.2	 Positioning
		21.6.3	 Arthroscopy
		21.6.4	 Open Procedure
			21.6.4.1	 Exposure
			21.6.4.2	 Osteotomy
			21.6.4.3	 Fixation
			21.6.4.4	 Additional Procedures for Instability
	21.7	 Postoperative Management
	21.8	 Complications and Prevention
	21.9	 Pearls and Pitfalls
		21.9.1	 Pearls
		21.9.2	 Pitfalls
	21.10	 Outcomes
	21.11	 Conclusions
	References
22: Tibial Tubercle Osteotomies: Techniques and Distalization
	22.1	 Introduction
	22.2	 Indications
	22.3	 Surgical Technique
		22.3.1	 Installation
		22.3.2	 Arthroscopy
		22.3.3	 ATT Transfer
		22.3.4	 Patellar Tenodesis
	22.4	 Postoperative Care
	22.5	 Complications
	22.6	 Conclusion
	References
23: Tibial Tubercle Osteotomies: Techniques and Medialization
	23.1	 Introduction
	23.2	 Patellofemoral Biomechanics of Medialization
	23.3	 Indications
	23.4	 Surgical Technique
		23.4.1	 Historical Perspective
			23.4.1.1 Skin Incision
			23.4.1.2 Medial Reefing
			23.4.1.3 Lateral Release
			23.4.1.4 Tibial Tubercle Osteotomy
		23.4.2	 Surgical Procedure
			23.4.2.1	 Patient Positioning and Sterile Field
			23.4.2.2 Lateral Release
			23.4.2.3	 Tibial Tuberosity Medial Displacement
			23.4.2.4 Medial Reefing
	23.5	 Postoperative Treatment
	23.6	 Discussion
	23.7	 Conclusions
	References
24: Complications of Tibial Tubercle Osteotomies
	24.1	 Introduction
	24.2	 Distalization of the Tibial Tubercle
		24.2.1	 Minimize the Risk of Complication in Distalization
	24.3	 Anteromedialization of the Tibial Tubercle
		24.3.1	 Minimize the Risk of Complication in AMZ
	24.4	 Considerations for Distalizing or AMZ Osteotomies
		24.4.1	 Minimize the Risk of Complication in Both Osteotomies
	24.5	 Nonunion
		24.5.1	 Minimize the Risk of Nonunion
	24.6	 Tibial Tubercle Fracture
		24.6.1	 Minimize the Risk of Tibial Tubercle Fracture
	24.7	 Proximal Tibia Fracture
		24.7.1	 Minimize the Risk of Proximal Tibia Fracture
	24.8	 Postoperative Rehabilitation
		24.8.1	 Minimize the Risk of Complications During Postoperative Rehabilitation
	References
25: Trochleoplasty: Indications and Results
	25.1	 Indications
		25.1.1	 Associated Procedures
	25.2	 Results
		25.2.1	 Biomechanical Studies
		25.2.2	 Clinical Results
		25.2.3	 Lyon Technique
		25.2.4	 Bereiter Technique
		25.2.5	 Goutallier Technique
		25.2.6	 Systematic Reviews
		25.2.7	 Our Results
		25.2.8	 Complications
	25.3	 Conclusion
	References
26: Patellofemoral Pain, Instability, and Arthritis Trochleoplasty Techniques: Arthroscopy
	26.1	 Introduction
	26.2	 Indication
	26.3	 Technique
		26.3.1	 Preparation and Portal Placement
		26.3.2	 Creation of the Cartilage Flap
		26.3.3	 Formation and Shaping of a Deeper Trochlear Groove
		26.3.4	 Fixation of the Cartilage Flap
			26.3.4.1	 Postoperative Regime
	26.4	 Results
	26.5	 Complications
	26.6	 Discussion
	26.7	 Conclusion
	References
27: Trochleoplasty Techniques: Sulcus Deepening acc. Bereiter
	27.1	 Indication
	27.2	 Surgical Technique
	27.3	 Postoperative Protocol
	References
28: Trochleoplasty Techniques: Deepening Lyon
	28.1	 Introduction
	28.2	 Indications
	28.3	 Contraindications
	28.4	 Surgical Technique
	28.5	 Postoperative Care
	28.6	 Conclusion
	References
29: Lengthening Osteotomy with or Without Elevation of the Lateral Trochlear Facet
	29.1	 Introduction
	29.2	 Physical Examination
	29.3	 Imaging
		29.3.1	 Radiographs
		29.3.2	 MR Measurements
	29.4	 Surgery
		29.4.1	 Lengthening
		29.4.2	 Elevation
	29.5	 Postoperative Care
	29.6	 Conclusions
	References
30: Trochleoplasty Techniques: Recession Osteotomy
	30.1	 Introduction
	30.2	 Indications
	30.3	 Surgical Technique
	30.4	 Conclusions
	References
31: Trochleoplasty Techniques: Complications
	31.1	 Preoperative Complications
	31.2	 Intra-/Peri-/Postoperative Complications
	31.3	 Complications in the Follow-Up
	References
32: Lateral Release of the Lateral Patellar Retinaculum: Literature Review for Select Patellofemoral Disorders
	32.1	 Introduction
	32.2	 Physical Examination
	32.3	 Patellofemoral Instability
	32.4	 Patellofemoral Pain
	32.5	 Isolated Patellofemoral Osteoarthritis
	32.6	 Complications
	32.7	 Conclusion
	References
33: Surgical Rehabilitation for Select Patellar Stabilizing Procedures
	33.1	 Introduction
	33.2	 Course of Care
	33.3	 Phase 0: Preoperative Rehabilitation (“Pre-Habilitation”)
	33.4	 Phase I: Rehabilitation—Acute Postoperative Management
		33.4.1	 Effusion Management
		33.4.2	 Weight-Bearing Status and Gait Progressions
		33.4.3	 Joint Range of Motion
		33.4.4	 Strengthening
	33.5	 Clinical Pearls for Common PostOperative Complications in Phase I
	33.6	 Phase II: Recovery of Function and Fitness
		33.6.1	 PF Biomechanical Considerations for Safe PostOperative Strength Progressions
	33.7	 Phase III: Return to Activity and Return to Run
		33.7.1	 Return to Run
	33.8	 Phase IV: Return to Sport Training and Sport Reentry
	33.9	 Complications
	33.10	 Conclusion
	References
34: Designing a Rehabilitation Programme for the Patient with Patellofemoral Pain
	34.1	 Introduction
	34.2	 Where Does the Pain Come From?
	34.3	 Local, Proximal and Distal Mechanics: What Does the Current Biomechanical Evidence Tell Us?
	34.4	 Limitations of Current Measurements
	34.5	 The Importance of Considering Dynamic and Skeletal Alignment During Assessment and Treatment
	34.6	 How to Design a Rehabilitation Programme?
	34.7	 Study Methodology
	34.8	 Static Alignment Evaluation
	34.9	 Assessment of Muscle Length
	34.10	 Dynamic Alignment Evaluation
	34.11	 Exercise Prescription
	34.12	 Dosage of Exercise
	34.13	 Study Outcomes
	34.14	 Adjunct Treatment Options
	34.15	 Conclusion
	References
35: Obligatory Dislocators, Dislocation in Flexion
	35.1	 Introduction
	35.2	 Treatment
	35.3	 Conclusion
	References
36: Is There an Indication for Patella Osteotomies?
	36.1	 Introduction
	36.2	 Historical Evidences for Patellar Osteotomies
	36.3	 Patellar Osteotomies in Objective Patellar Dislocation
	36.4	 Medial Closing Wedge Patellar Osteotomy
		36.4.1	 Preoperative Planning
		36.4.2	 Surgical Technique and Rehabilitation
	36.5	 Discussion
	36.6	 Conclusions
	References
37: Is There an Indication for Correcting a Valgus Knee?
	37.1	 Introduction
	37.2	 Indications and Contraindications
	37.3	 Surgical Technique
	37.4	 Results
	37.5	 Conclusion
	References
38: Simple to Complex Cases
	38.1	 Case 1
	38.2	 Case 2
	38.3	 Case 3
39: Isolated Patellofemoral Osteoarthritis: Natural History and Clinical Presentation
	39.1	 Introduction
	39.2	 Epidemiology
	39.3	 Patient History and Physical Examination
	39.4	 Radiographic Analysis of Isolated PFOA
	39.5	 Etiologies of PFOA
		39.5.1	 Primary PFOA
			39.5.1.1 Radiological Features
		39.5.2	 Post-instability PFOA
			39.5.2.1 Dislocation
			39.5.2.2 Extensor Mechanism Malalignment
			39.5.2.3 Lack of Congruency Between the Patella and the Trochlea
			39.5.2.4 Patellar Height
			39.5.2.5 Radiological Features
				Trochlear Dysplasia
				TT-TG Distance
				Patellar Height
		39.5.3	 Post-traumatic PFOA
			39.5.3.1 Radiological Features
		39.5.4	 PF Chondrocalcinosis
			39.5.4.1 Radiological Features
	39.6	 Predisposing Factors to PFOA
		39.6.1	 Trochlear Dysplasia
		39.6.2	 Dysplasia of the Patella
		39.6.3	 Other Factors
	39.7	 Natural History and Treatment Implications
	39.8	 Therapeutic Consequences
		39.8.1	 Patellofemoral Arthritis Without Dysplasia/PFOA with Normal Patellofemoral Anatomy
		39.8.2	 Patellofemoral Arthritis with Dysplasia/PFOA with Abnormal Patellofemoral Anatomy
	References
40: Techniques for Cartilage Restoration in the Patellofemoral Joint
	40.1	 Microfractures
		40.1.1	 Rationale
		40.1.2	 Technique
		40.1.3	 Results
	40.2	 Osteochondral Autologous Transplantation (OAT)
		40.2.1	 Rationale
		40.2.2	 Technique
		40.2.3	 Results
	40.3	 Osteochondral Allograft (OCA)
		40.3.1	 Rationale
		40.3.2	 Technique
		40.3.3	 Results
	40.4	 Autologous Chondrocyte Implantation (ACI)
		40.4.1	 Rationale
		40.4.2	 Technique
		40.4.3	 Results
	40.5	 Matrix-Assisted Autologous Chondrocyte Transplantation (MACT)
		40.5.1	 Rationale
		40.5.2	 Technique
		40.5.3	 Results
	40.6	 Bone Marrow-Derived Cell Transplantation (BMCT)
		40.6.1	 Rationale
		40.6.2	 Technique
		40.6.3	 Results
	40.7	 Cell-Free Chondral Scaffolds
		40.7.1	 Rationale
		40.7.2	 Technique
		40.7.3	 Results
	40.8	 Cell-Free Osteochondral Scaffolds
		40.8.1	 Rationale
		40.8.2	 Technique
		40.8.3	 Results
	40.9	 Conclusions
	References
41: Isolated Patellofemoral Unipolar Cartilage Lesions: When to Intervene
	41.1	 Introduction
	41.2	 Review of Applied Anatomy and Biomechanics
		41.2.1	 Normal Osteochondral Structure, Anatomy, and Dysplasias
		41.2.2	 Limb Alignment, PF Alignment, and Patella Positioning
		41.2.3	 PF Biomechanics, Contact Area, and Pressure
		41.2.4	 Etiology
		41.2.5	 Patellar Instability (Fig. 41.3) (Video 41.1)
		41.2.6	 Chronic Malalignment/Maltracking Without Instability
		41.2.7	 Direct Trauma (Fig. 41.4)
		41.2.8	 Repetitive Microtrauma (Fig. 41.5)
		41.2.9	 Idiopathic (Fig. 41.6)
	41.3	 Patient Evaluation
		41.3.1	 Physical Examination
		41.3.2	 Imaging Studies
	41.4	 Treatment
		41.4.1	 Which and Why Lesions Are Symptomatic?
		41.4.2	 Nonoperative Treatment
		41.4.3	 Operative Treatment
	41.5	 Conclusions
	References
42: Partial Lateral Patella Facetectomy and Management of the Lateral Soft Tissues
	42.1	 Introduction
	42.2	 Concomitant Procedures
	42.3	 Case Study
	42.4	 Treatment Plan
	42.5	 Surgical Indications and Contraindications
	42.6	 Surgical Technique
		42.6.1	 Arthroscopic Technique
		42.6.2	 Open Technique
	42.7	 Arthroscopic vs. Open
	42.8	 Pearls and Pitfalls
		42.8.1	 Pearls
		42.8.2	 Pitfalls
	42.9	 Rehabilitation
	42.10	 Outcomes and Complications
		42.10.1 Concomitant Total Knee Arthroplasty
	42.11	 Conclusion
	References
43: Arthroplasty Design of the Patellofemoral Joint
	43.1	 Introduction
	43.2	 Design Rationale
	43.3	 The Natural Trochlea
	43.4	 The Prosthetic Trochlea
	43.5	 The Ideal PFA Prosthesis
	43.6	 The Future
	References
44: Indications for Patellofemoral Arthroplasty in Isolated Patellofemoral Arthritis
	References
45: Complications of Patellofemoral Arthroplasty
	45.1	 Introduction
	45.2	 Indications
	45.3	 Failure Due to Progression of Tibiofemoral Arthritis
	45.4	 Choice of Implant
	45.5	 Surgical Technique
	45.6	 Revision to Total Knee Arthroplasty
	45.7	 Summary
	References
46: Review of Patella Disorders in Skeletally Immature Patients
	46.1	 Osgood-Schlatter Disease
		46.1.1	 Nature of the Disease
		46.1.2	 Clinical Findings and Diagnostics
		46.1.3	 Treatment Options
	46.2	 Sinding-Larsen-Johansson Syndrome (SLJ)
		46.2.1	 Nature of the Disease
		46.2.2	 Clinical Findings and Diagnostics
		46.2.3	 Treatment Options
	46.3	 Bipartite Patella
		46.3.1	 Nature of the Disease
		46.3.2	 Clinical Findings and Diagnostics
		46.3.3	 Treatment Options
	46.4	 Trochlear and Patellar Juvenile Osteochondritis Dissecans (JOCD) of the Knee
		46.4.1	 Nature of the Disease
		46.4.2	 Clinical Findings and Diagnostics
		46.4.3	 Treatment Options
	46.5	 Patellar Instability
	46.6	 Acute Dislocation of the Patella
	46.7	 Recurrent Dislocation of the Patella
	46.8	 Obligatory Dislocation
	References
47: Specific Procedures for Pediatric Dislocation
	47.1	 Evaluation of the Pediatric Patient with Patellar Dislocation
	47.2	 Risk Factors for Recurrent Patellar Dislocation
	47.3	 Pediatric Options for Medial Patellofemoral Ligament Reconstruction
		47.3.1	 Doubled Two-Limbed Free Hamstring Graft
		47.3.2	 Medial Quadriceps Tendon Femoral Ligament Reconstruction
		47.3.3	 Hamstring Graft with the Use of Adductor Magnus Tendon as Femoral Attachment Site
		47.3.4	 Pedicled Quadriceps Tendon
		47.3.5	 Pedicled Adductor Magnus Tendon
	47.4	 Distal Realignment Options
		47.4.1	 Nietosvaara Technique
		47.4.2	 Roux-Goldthwait Procedure
		47.4.3	 Patellar Tendon Transfer
		47.4.4	 Patellar Tendon Shortening
	47.5	 Guided Growth
	References
48: Trochleoplasty in Children and Adolescents
	48.1	 Introduction
	48.2	 Indications
	48.3	 Contraindication
	48.4	 Technique
	48.5	 Rehabilitation
	48.6	 Discussion
	48.7	 Summary
	References
49: Patellar Tendon Shortening
	49.1	 Introduction
	49.2	 Surgical Indications
	49.3	 Surgical Method
	49.4	 Postoperative Care
	49.5	 Clinical Results
	References
50: Tibial Tubercle Procedure: Old Osgood-Schlatter
	50.1	 Introduction
	50.2	 Operative Techniques
		50.2.1	 Ossicle Excision and Tuberculoplasty
			50.2.1.1	 Open Surgery
			50.2.1.2	 Endoscopic Surgery
		50.2.2	 Reduction Osteotomy of the Tibial Tubercle
	50.3	 Conclusions
	References
51: Derotational Osteotomies in Patella Instability
	51.1	 Introduction
	51.2	 Indication
	51.3	 Measurement
	51.4	 Surgical Treatment
		51.4.1	 Distal Femoral Derotational Osteotomy
		51.4.2	 Tibial Derotational Osteotomy
		51.4.3	 Combined Procedures at the Femur and Tibia
	51.5	 Aftercare
	51.6	 Complications
	51.7	 Outcomes
	51.8	 Summary
	References
52: Guided Growth Surgery
	52.1	 Introduction
	52.2	 Planning for Surgery
	52.3	 Surgical Technique
	52.4	 Results for Guided Growth Surgery
	References